Hi Ian,
hmm, I don't have experiences with your DB or Apache 2.0. Does the docu says, ez will work with Apache 2.0? For me (using Apache 1.3), the rewrite rules worked nicely.
You can turn on debug info in either setup.ini or site.ini (I don't know right now) or in the corresponding override files, if there are any in the settings/override dir.
There is a whole section about Debug output, I think, the first switch is the master switch to turn debug on. It's documented. Maybe that will help you.