CHM to Epub conversion error

[pweasel]

i'm trying to convert a CHM that has a problem on the first page (of the CHM)

[IMG][/IMG]

and gives me this error when trying to EPUBify it :

calibre, version 0.8.21
ERROR: Conversion Error: <b>Failed</b>: Convert book 1 of 1 (Microsoft. Press.Microsoft.Dot.NET.and.J2EE. Interoperability.)

Convert book 1 of 1 (Microsoft. Press.Microsoft.Dot.NET.and.J2EE. Interoperability.)
Resolved conversion options
calibre version: 0.8.21
{'asciiize': False,
'author_sort': None,
'authors': None,
'base_font_size': 0.0,
'book_producer': None,
'change_justification': u'original',
'chapter': u"//*[((name()='h1' or name()='h2') and re:test(., 'chapter|book|section|part|prologue|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_split_on_page_breaks': False,
'duplicate_links_in_toc': False,
'enable_heuristics': True,
'epub_flatten': False,
'extra_css': None,
'extract_to': None,
'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 0x05F581D0>,
'insert_blank_line': False,
'insert_blank_line_size': 0.5,
'insert_metadata': False,
'isbn': None,
'italicize_common_cases': True,
'keep_ligatures': False,
'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,
'no_chapters_in_toc': False,
'no_default_epub_cover': False,
'no_inline_navbars': False,
'no_svg_cover': False,
'output_profile': <calibre.customize.profiles.iPadOutput object at 0x05F58470>,
'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': 'd:\\pweasel\\tmp\\calibre_0.8.21_tmp_rais9f\\02ul di.opf',
'remove_fake_margins': True,
'remove_first_image': False,
'remove_paragraph_spacing': False,
'remove_paragraph_spacing_indent_size': 1.5,
'renumber_headings': True,
'replace_scene_breaks': u'',
'series': None,
'series_index': None,
'smarten_punctuation': False,
'sr1_replace': None,
'sr1_search': None,
'sr2_replace': None,
'sr2_search': None,
'sr3_replace': None,
'sr3_search': None,
'tags': None,
'timestamp': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 6,
'unsmarten_punctuation': False,
'unwrap_lines': True,
'use_auto_toc': False,
'verbose': 2}
InputFormatPlugin: CHM Input running
on d:\pweasel\tmp\calibre_0.8.21_tmp_rais9f\53ostu.ch m
Processing CHM...
tdir=d:\pweasel\tmp\calibre_0.8.21_tmp_rais9f\xv9o lk_chm2oeb
stream.name=d:\pweasel\tmp\calibre_0.8.21_tmp_rais 9f\53ostu.chm
Opening CHM file
Extracting CHM to d:\pweasel\tmp\calibre_0.8.21_tmp_rais9f\xv9olk_ch m2oeb
Python function terminated unexpectedly
Unable to locate '/backcover.html' within CHM file 'd:\pweasel\tmp\calibre_0.8.21_tmp_rais9f\53ostu.c hm' (Error Code: 1)
Traceback (most recent call last):
File "site.py", line 132, in main
File "site.py", line 109, in run_entry_point
File "site-packages\calibre\utils\ipc\worker.py", line 187, 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 947, in run
File "site-packages\calibre\customize\conversion.py", line 204, in __call__
File "site-packages\calibre\ebooks\chm\input.py", line 58, in convert
File "site-packages\calibre\ebooks\chm\metadata.py", line 136, in get_metadata_from_reader
File "site-packages\calibre\ebooks\chm\reader.py", line 94, in GetFile
calibre.ebooks.chm.reader.CHMError: Unable to locate '/backcover.html' within CHM file 'd:\pweasel\tmp\calibre_0.8.21_tmp_rais9f\53ostu.c hm'

is there anything that can be done?
thanks, PW