Cannot change default bug priority or severity - two questions

So in our local Bugzilla system (Running Windows Server and using IIS Bugzilla 5.0.6), our SQA group can no longer change the default bug priority or severity settings.  This database passes the sanity check, but it has been in existence some time Christmas 2007.  It was a project by me, and there have been many fingers.  It started on my laptop, exported to a customer machine, upgraded a couple of times to  different hardware and now lives on a VM somewhere in the corporate cloud.

  With that said,  the obvious question is has anyone else seen something like this?

  Second question - I have found the IIS log files - useless.  Where are the Bugzilla log files by default?

Regards,

Chg