Well, I saw that DotNetNuke (http://www.dotnetnuke.com) had released new versions of their portal software, and since this site uses that software and I wanted to take advantage of some of the new features, I downloaded and installed the upgrade.
Unfortunately, I should have read the fine print a little more closely... 
It turns out they made some major plumbing changes, in particular to the User Membership and Roles. After doing the upgrade, I suddenly lost all of my unauthorized users (people who registered for the site, but hadn't returned to input the validation code). Normally, I keep unauthorized users for 30 days, if you haven't logged in by then, I figure you moved on and so I remove the account information. But right now, if your account falls into this category, the upgrade has not so politely deleted it. So if you received a validation email, but had yet to login to the site, drop me an email using the "Contact Us" menu to the left and I will see if your account still exists. If not, you may have to re-register.
Also giving me trouble is the new Announcements module. While I agree with the new changes, the module seems to be ignoring any HTML formatting that I have applied. The instructions for downloading the source code using Subversion are now completely hosed, and I will have to work on getting that cleaned up.
If this upgrade proves to be too problematic, I can go back to the previous version using my backups, but for the moment I'm trying to move forward with this build. Please let me know if you experience any problems whatsoever, and I will do my best to make sure you are satisfied with your visit here.
I apologize for any inconvenience, in the future more steps will be taken to try and smooth out any upgrades to the web site.