[TheSpanishInq.]

Until a few monts ago I used win7 and conversion by Calibre worked fine for me. Since I started to use Linux (Ubuntu 12.10 64 bit) and Calibre for Linux it stopped working. I even tried a Win version with Wine: same result.
Am I doing something wrong? Are there too many options Checked? Help please.
Here are 2 error messages and the debug files as a ZIP attachment:

Spoiler:

calibre, version 0.9.16 (linux2, isfrozen: True)
Conversiefout: Mislukt: Boek 1 van 1 (Gabriel's Inferno) converteren

Boek 1 van 1 (Gabriel's Inferno) converteren
Resolved conversion options
calibre version: 0.9.16
{'asciiize': False,
'author_sort': None,
'authors': None,
'base_font_size': 0.0,
'book_producer': None,
'change_justification': u'justify',
'chapter': u"//*[((name()='h1' or name()='h2') and re:test(., '\\s*((chapter|book|section|part)\\s+)|((prolog|pr ologue|epilogue)(\\s+|$))', 'i')) or @class = 'chapter']",
'chapter_mark': u'pagebreak',
'comments': None,
'cover': u'/tmp/calibre_0.9.16_tmp_KfQu6o/Vg_vzY.jpeg',
'debug_pipeline': None,
'dehyphenate': True,
'delete_blank_paragraphs': True,
'disable_font_rescaling': False,
'dont_split_on_page_breaks': False,
'duplicate_links_in_toc': False,
'embed_font_family': u'Arial',
'enable_heuristics': False,
'epub_flatten': False,
'extra_css': None,
'extract_to': None,
'filter_css': u'',
'fix_indents': True,
'flow_size': 260,
'font_size_mapping': None,
'format_scene_breaks': True,
'html_unwrap_factor': 0.4,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.InputProfile object at 0x295ea10>,
'insert_blank_line': False,
'insert_blank_line_size': 0.5,
'insert_metadata': True,
'isbn': None,
'italicize_common_cases': True,
'keep_ligatures': True,
'language': None,
'level1_toc': None,
'level2_toc': None,
'level3_toc': None,
'line_height': 0.0,
'linearize_tables': False,
'margin_bottom': 5.0,
'margin_left': 5.0,
'margin_right': 5.0,
'margin_top': 5.0,
'markup_chapter_headings': True,
'max_toc_links': 50,
'minimum_line_height': 120.0,
'new_pdf_engine': False,
'no_chapters_in_toc': False,
'no_default_epub_cover': False,
'no_images': False,
'no_inline_navbars': False,
'no_svg_cover': False,
'output_profile': <calibre.customize.profiles.TabletOutput object at 0x2964510>,
'page_breaks_before': u"//*[name()='h1' or name()='h2']",
'prefer_metadata_cover': True,
'preserve_cover_aspect_ratio': False,
'pretty_print': True,
'pubdate': None,
'publisher': None,
'rating': None,
'read_metadata_from_opf': u'/tmp/calibre_0.9.16_tmp_KfQu6o/d9npJ5.opf',
'remove_fake_margins': True,
'remove_first_image': False,
'remove_paragraph_spacing': True,
'remove_paragraph_spacing_indent_size': 1.5,
'renumber_headings': True,
'replace_scene_breaks': u'',
'search_replace': '[]',
'series': None,
'series_index': None,
'smarten_punctuation': True,
'sr1_replace': None,
'sr1_search': None,
'sr2_replace': None,
'sr2_search': None,
'sr3_replace': None,
'sr3_search': None,
'start_reading_at': None,
'subset_embedded_fonts': True,
'tags': None,
'timestamp': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 10,
'unsmarten_punctuation': False,
'unwrap_factor': 0.45,
'unwrap_lines': True,
'use_auto_toc': False,
'verbose': 2}
InputFormatPlugin: PDF Input running
on /tmp/calibre_0.9.16_tmp_KfQu6o/m2cZkK.pdf
Converting file to html...
Retrieving document metadata...
Generating manifest...
Rendering manifest...
Parsing all content...
Parsing index.html ...
Initial parse failed, using more forgiving parsers
Parsing index.html as HTML
Generating default TOC from spine...
Merging user specified metadata...
Detecting structure...
Auto generated TOC with 43 entries.
Inserting metadata into book...
Flattening CSS and remapping font sizes...
Embedding font: Arial
WARNING Property: Unknown Property name. [1:34: panose-1]
WARNING Property: Unknown Property name. [1:41: panose-1]
WARNING Property: Unknown Property name. [1:39: panose-1]
WARNING Property: Unknown Property name. [1:46: panose-1]
Source base font size is 12.00000pt
Removing fake margins...
Found 2 items of level: div_1
Found 1 items of level: div_2
Found 16936 items of level: p_1
div_1 left margin stats: Counter()
div_1 right margin stats: Counter()
div_2 left margin stats: Counter()
div_2 right margin stats: Counter()
p_1 left margin stats: Counter({u'0': 16936})
p_1 right margin stats: Counter({u'0': 16936})
Traceback (most recent call last):
File "site.py", line 58, in main
File "site-packages/calibre/utils/ipc/worker.py", line 186, in main
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 31, in gui_convert_override
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 25, in gui_convert
File "site-packages/calibre/ebooks/conversion/plumber.py", line 1130, in run
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 30, in __call__
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 179, in find_font_usage
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 285, in find_usage_in
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 283, in find_usage_in
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 185, in elem_style
AttributeError: 'NoneType' object has no attribute 'split'

Spoiler:

calibre, version 0.9.16 (linux2, isfrozen: True)
Conversiefout: Mislukt: Boek 1 van 1 (01 - Bob Shaw - [Novelette] Frost Animals (v1.0) (html)) converteren

Boek 1 van 1 (01 - Bob Shaw - [Novelette] Frost Animals (v1.0) (html)) converteren
Processing archive...
Resolved conversion options
calibre version: 0.9.16
{'asciiize': False,
'author_sort': None,
'authors': None,
'base_font_size': 0.0,
'book_producer': None,
'breadth_first': False,
'change_justification': u'justify',
'chapter': u"//*[((name()='h1' or name()='h2') and re:test(., '\\s*((chapter|book|section|part)\\s+)|((prolog|pr ologue|epilogue)(\\s+|$))', 'i')) or @class = 'chapter']",
'chapter_mark': u'pagebreak',
'comments': None,
'cover': None,
'debug_pipeline': None,
'dehyphenate': True,
'delete_blank_paragraphs': True,
'disable_font_rescaling': False,
'dont_package': False,
'dont_split_on_page_breaks': False,
'duplicate_links_in_toc': False,
'embed_font_family': u'Arial',
'enable_heuristics': True,
'epub_flatten': False,
'extra_css': None,
'extract_to': None,
'filter_css': u'',
'fix_indents': True,
'flow_size': 260,
'font_size_mapping': None,
'format_scene_breaks': True,
'html_unwrap_factor': 0.4,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.InputProfile object at 0x225fa10>,
'insert_blank_line': False,
'insert_blank_line_size': 0.5,
'insert_metadata': True,
'isbn': None,
'italicize_common_cases': True,
'keep_ligatures': True,
'language': None,
'level1_toc': None,
'level2_toc': None,
'level3_toc': None,
'line_height': 0.0,
'linearize_tables': False,
'margin_bottom': 5.0,
'margin_left': 5.0,
'margin_right': 5.0,
'margin_top': 5.0,
'markup_chapter_headings': True,
'max_levels': 5,
'max_toc_links': 50,
'minimum_line_height': 120.0,
'no_chapters_in_toc': False,
'no_default_epub_cover': False,
'no_inline_navbars': False,
'no_svg_cover': False,
'output_profile': <calibre.customize.profiles.TabletOutput object at 0x2264510>,
'page_breaks_before': u"//*[name()='h1' or name()='h2']",
'prefer_metadata_cover': False,
'preserve_cover_aspect_ratio': False,
'pretty_print': True,
'pubdate': None,
'publisher': None,
'rating': None,
'read_metadata_from_opf': u'/tmp/calibre_0.9.16_tmp_KfQu6o/irHL9T.opf',
'remove_fake_margins': True,
'remove_first_image': False,
'remove_paragraph_spacing': True,
'remove_paragraph_spacing_indent_size': 1.5,
'renumber_headings': True,
'replace_scene_breaks': u'',
'search_replace': '[]',
'series': None,
'series_index': None,
'smarten_punctuation': True,
'sr1_replace': None,
'sr1_search': None,
'sr2_replace': None,
'sr2_search': None,
'sr3_replace': None,
'sr3_search': None,
'start_reading_at': None,
'subset_embedded_fonts': True,
'tags': None,
'timestamp': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 10,
'unsmarten_punctuation': False,
'unwrap_lines': True,
'use_auto_toc': False,
'verbose': 2}
InputFormatPlugin: HTML Input running
on /tmp/calibre_0.9.16_tmp_KfQu6o/ORarUE_plumber_archive/Terry Carr (ed) - Universe 09 - 01 - Bob Shaw - [Novelette] Frost Animals (v1.0) (html).html
Language not specified
Building file list...
Found files...
HTMLFile:0:a:/tmp/calibre_0.9.16_tmp_KfQu6o/ORarUE_plumber_archive/Terry Carr (ed) - Universe 09 - 01 - Bob Shaw - [Novelette] Frost Animals (v1.0) (html).html
Normalizing filename cases
Rewriting HTML links
Parsing Terry Carr (ed) - Universe 09 - 01 - Bob Shaw - [Novelette] Frost Animals (v1.0) (html).html ...
********* Heuristic processing HTML *********
There are 351 blank lines. 0.500713266762 percent blank
minimum chapters required are: 3
found 0 pre-existing headings
Total wordcount is: 15059, Average words per section is: 15059, Marked up 0 chapters
deleting blank lines
Hard line breaks check returned False
Median line length is 255, calculated with html format
Fixing hyphenated content
Looking for more split points based on punctuation, currently have 0
Formatting scene breaks
Initial parse failed, using more forgiving parsers
Parsing Terry Carr (ed) - Universe 09 - 01 - Bob Shaw - [Novelette] Frost Animals (v1.0) (html).html as HTML
Merging user specified metadata...
Detecting structure...
Auto generated TOC with 0 entries.
Inserting metadata into book...
Flattening CSS and remapping font sizes...
Embedding font: Arial
Property: Unknown Property name. [1:34: panose-1]
Property: Unknown Property name. [1:41: panose-1]
Property: Unknown Property name. [1:39: panose-1]
Property: Unknown Property name. [1:46: panose-1]
Source base font size is 12.00000pt
Removing fake margins...
Found 3 items of level: div_1
Found 1 items of level: div_2
Found 351 items of level: p_2
div_1 left margin stats: Counter({u'': 1})
div_1 right margin stats: Counter({u'': 1})
div_2 left margin stats: Counter()
div_2 right margin stats: Counter()
p_2 left margin stats: Counter({u'0': 351})
p_2 right margin stats: Counter({u'0': 351})
Traceback (most recent call last):
File "site.py", line 58, in main
File "site-packages/calibre/utils/ipc/worker.py", line 186, in main
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 31, in gui_convert_override
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 25, in gui_convert
File "site-packages/calibre/ebooks/conversion/plumber.py", line 1130, in run
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 30, in __call__
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 179, in find_font_usage
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 285, in find_usage_in
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 283, in find_usage_in
File "site-packages/calibre/ebooks/oeb/transforms/subset.py", line 185, in elem_style
AttributeError: 'NoneType' object has no attribute 'split'