epub to mobi error when including images

[HarrisS]

This could be answered but I am getting an error when trying to convert from epub to mobi. I created the epub in InDesign CS3. The only time I get the error is when I want to use images as the start of the chapter. My image files are 100 x 71 pixels and 20.8 Kb, so they should not be too large.
Help please!

ERROR: Conversion Error: <b>Failed</b>: Convert book 1 of 1 (Book 1)

Convert book 1 of 1 (Book 1)
Resolved conversion options
calibre version: 0.7.28
{'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': '/tmp/calibre_0.7.28_tmp_6J5qWD/calibre_0.7.28_dRCoV2.jpeg',
'debug_pipeline': None,
'disable_font_rescaling': False,
'dont_compress': False,
'extra_css': None,
'font_size_mapping': None,
'footer_regex': u'(?i)(?<=<hr>)((\\s*<a name=\\d+></a>((<img.+?>)*<br>\\s*)?\\d+<br>\\s*.*?\\s*)|(\\s* <a name=\\d+></a>((<img.+?>)*<br>\\s*)?.*?<br>\\s*\\d+))(?=<br>)' ,
'header_regex': u'(?i)(?<=<hr>)((\\s*<a name=\\d+></a>((<img.+?>)*<br>\\s*)?\\d+<br>\\s*.*?\\s*)|(\\s* <a name=\\d+></a>((<img.+?>)*<br>\\s*)?.*?<br>\\s*\\d+))(?=<br>)' ,
'html_unwrap_factor': 0.40000000000000002,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.InputProfile object at 0x66d63b0>,
'insert_blank_line': False,
'insert_metadata': False,
'isbn': None,
'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,
'max_toc_links': 50,
'no_chapters_in_toc': False,
'no_inline_navbars': True,
'no_inline_toc': False,
'output_profile': <calibre.customize.profiles.KindleOutput object at 0x66d6690>,
'page_breaks_before': u'/',
'personal_doc': u'[PDOC]',
'prefer_author_sort': False,
'prefer_metadata_cover': False,
'preprocess_html': False,
'pretty_print': False,
'pubdate': None,
'publisher': None,
'rating': None,
'read_metadata_from_opf': '/tmp/calibre_0.7.28_tmp_6J5qWD/calibre_0.7.28_482j1g.opf',
'remove_first_image': False,
'remove_footer': False,
'remove_header': False,
'remove_paragraph_spacing': False,
'remove_paragraph_spacing_indent_size': 1.5,
'rescale_images': False,
'series': None,
'series_index': None,
'smarten_punctuation': False,
'tags': None,
'timestamp': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 6,
'toc_title': None,
'use_auto_toc': False,
'verbose': 2}
InputFormatPlugin: EPUB Input running
on /Users/Teacher/Desktop/Shannon/Books/Unknown/Book 1 (31)/Book 1 - Unknown.epub
Parsing all content...
Parsing OEBPS/Chapter_1.xhtml ...
Parsing OEBPS/Chapter_2.xhtml ...
Parsing OEBPS/template.css ...
Reading TOC from NCX...
Merging user specified metadata...
Detecting structure...
Flattening CSS and remapping font sizes...
Source base font size is 12.00000pt
Cleaning up manifest...
Trimming unused files from manifest...
Parsing stylesheet.css ...
Trimming 'OEBPS/images/Chapter%20I_fmt.jpeg' from manifest
Python function terminated unexpectedly: OEBPS/images/Chapter%20I_fmt.jpeg
Creating MOBI Output...
Generating in-line TOC...
Applying case-transforming CSS...
Parsing manglecase.css ...
Parsing tocstyle.css ...
Rasterizing SVG images...
Converting XHTML to Mobipocket markup...
Serializing markup content...
Compressing markup content...
Generating flat CTOC ...
CNCX utilization: 1 record, 0% full
Indexing navPoints ...
Generating INDX ...
Serializing images...
Traceback (most recent call last):
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.6/site.py", line 147, in main
return run_entry_point()
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.6/site.py", line 116, in run_entry_point
return getattr(pmod, func)()
File "site-packages/calibre/utils/ipc/worker.py", line 107, in main
File "site-packages/calibre/gui2/convert/gui_conversion.py", line 24, in gui_convert
File "site-packages/calibre/ebooks/conversion/plumber.py", line 948, in run
File "site-packages/calibre/ebooks/mobi/output.py", line 181, in convert
File "site-packages/calibre/ebooks/mobi/writer.py", line 356, in __call__
File "site-packages/calibre/ebooks/mobi/writer.py", line 369, in _dump_stream
File "site-packages/calibre/ebooks/mobi/writer.py", line 384, in _generate_content
File "site-packages/calibre/ebooks/mobi/writer.py", line 1323, in _generate_images
KeyError: 'OEBPS/images/Chapter%20I_fmt.jpeg'

[ldolse]

This looks like some sort of bug.

Based on where the error occurs in the code it doesn't seem to like something about the filename - try an all lowercase name without any spaces.