This contains a few small fixes -
download from the previous post here.
It should now handle epubs without a <guide> element in the opf manifest (as per FFDL it seems) and now also won't fail if you happen to tick the "Rewrite CSS" option at the same time.
Please let me know here how you are getting on with it - particularly as I said previously Mac OS or Linux users as I am relying on you to test the changes there.
How about JSWolf - does the ePub now work with iBooks as you posted about?