I have a similar problem. I just ran a completed EPUB thorough the commandline version of epubchecker and most of my errors are in the form:
Code:
ERROR(RSC-005): How to Commit Suicide epub 12520.epub/OEBPS/Text/Text.xhtml(285,55): Error while parsing file: value of attribute "id" is invalid; must be a string matching the regular expression "[^\s]+"
I used id tags to set up navigation in the document. When I visually inspected them they seemed to be OK; each was unique and began with a character.
Perhaps if I know what "string matching the regular expression "[^\s]+" meant. Does it mean the ids must begin with a space?