epub conversion problems

[Reko]

I'm having some weird conversion problems no matter to what format I try to convert an epub into. I filed a ticket about it (http://bugs.calibre-ebook.com/ticket/6598), but was wondering if anyone has experienced this since it doesn't seem to be too big of a deal (just about permissions).

The rest of the bug is in the ticket, but here's the beef:
If I try to convert an epub into anything, it results into a failure below. I bought a Kindle from a friend and tried it at work, conversions etc. worked wonderfully (Calibre 0.7.15). When I got home and started doing the same exact thing, I get what's below.

What pops to my eye is the Python function terminated unexpectedly: CSSNamespaceRule: namespaceURI is readonly. and with the readonly tried changing an epub file into read+write for everyone, but it didn't do anything.

I've tried chmodding, changing the library locations, different conversion preferences, making sure I am the admin (OS X) etc. The funny thing is, there is a handful of epubs that do convert, but there's no clear pattern for any of it.

What I understand, it's could be some kind of a Python-related permissions problem or something, but I wouldn't know how to go change something like that.