I found and fixed at least part of the problem. It looks like an upgrade script may have failed between b1 and b2 and left at least part of the permissions settings in an unusable state... This seems to have happened because somehow a duplicate application name was in the aspnet_application table, and while this is not prevented by a constraint; cs is keyed off the application name (as are the aspnet login routines themselves...) I have purged the bad roles and user settings linked to the duplicate application name and manually updated the corrupt records...
I have also updated the site to the latest build, and placed the app in debug mode, which should provide us with more detailed error messages should the need arise.
Lastly, I am a tablet pc user, and committed to the community... If you are having trouble and you cant log in to post about it here; please contact me through my blog at http://blog.danbartels.com
Thank you for your patience in these matters
Dan