Sigh... 
I'm back again, with an inability to run the Community-Credit add-on, but this time, the problem is on just one of my sites. Unfortunately, it's the main site. ( http://Home.UltraTech-llc.com/)
Once we confirmed that ASP.NET 2.0 was needed to run the addon, I upgraded my internal website and was able to confirm that the module worked, as I posted earlier.
Early this morning, I upgraded my main site to ASP.NET 2.0, but I had quite a few issues, which turned out to be related to a conflict, it seems, between the CCredit add-on and at least one other add-on, most likely the URL remapping one. I didn't get my site back up until this afternoon, sometime, but in the meantime, I was able to upgrade my work installation to ASP.NET 2.0, and the CCredit module is running there as well.
Now, here's the fun part: I'm using the URL remapping module in all 3 locations, but I'm only experiencing failures on my public site.
Worse yet, except for the SQL connection strings in the Web.Config files used on my internal and public sites, all the other configuration files and DLLs are identical. I push all the changes from one source tree to either the internal web server, or via FTP to my external provider.
I need some help understanding what the issue is here, because I am almost certain that it is something simple that I'm overlooking -- again.
I'll zip up my root config files so that they can be shipped to whomever needs to look at them.
When I was troubleshooting this evening, I made one single change in the file at a time between uploads so that I could be sure exactly when it broke. Right now, on my public site, the code for CCredit is commented out, because if I enable it, the site breaks. (And, unfortunately, I can't get the errors to display remotely via mode="Off", so I can't see what the actually conflict message is).