Without inspecting in detail, this is probably:
https://sourceforge.net/apps/trac/pyxb/ticket/112
At this time there is no fix. I may have an opportunity to dig into
this in a month or so. You could assist by providing the modified
files you mention, so when it does get worked I can verify this
As the trac ticket suggests, it's partially fixed. You can see the current
solution in git, either by cloning the repository or browsing it in:
http://pyxb.git.sourceforge.net/git/gitweb.cgi?p=pyxb/pyxb;a=shortlog;h=refs/heads/trac/89
The most recent commit in that branch may be what you need.
Both of these are bugs.
https://sourceforge.net/apps/trac/pyxb/ticket/88 deals with the presence of
unicode characters in the input; there were several places where Python was
unhappy, but the specific one you ran into can be fixed by changing the
str(s) to unicode(s) in the MakeIdentifier definit
