Success. Wiping out the whole hosting account and restoring it from backups has fixed the problem.
I found that the problem affected all my domains hosted on that account, and every subfolder in all those domains.
I called GoDaddy.com and they were unable to fix it. The best I can figure is that somehow I caused it with a mix of adding and removing virtual directories.
I ended up having them cancel that whole hosting account and creating a new one, and then I restored all my domains from the backups.
As soon as the DNS info repopulates out through the net, I will be able to test to see if wiping clean and starting over… fixed the problem.
You are right! It happens with any other directory on my site!
So maybe this is a hosting set-up issue. At this point it seems it has nothing to do with bbPress.
I so appreciate that you folks were willing to take a few minutes to help! Because of you I am closer to sorting this out.
I will lurk around inside my hosting settings on GoDaddy.com and see if I can figure out what’s up.
I just tried again using Apple Safari 4.0.4 on a Win XP SP3 system. Problem is reproducible.
In all three browsers the OS stayed the same.
@chrishajer: Your test was also on Win XP. Common element?
Thanks.
Well, at least I’m not crazy. 
OK, I am using IE on a Win XP SP3 system. Problem is reproducible.
Now, I am using Firefox 3.0.16 on a Win XP SP3 system. Problem is reproducible.
@ipstenu
What OS are you using? And what browser?
Thanks for your help.
I should have mentioned I am on an IIS 7 server, so there is no .htaccess file, and I removed all “rewrite” rules from my web.config.
Thank you for clicking, and for reporting that the site is working fine for you.
That must mean my problem is local only to my PC. How could that be?
It is definitely still showing the same problem. Just tried again even as I was typing this.
???
Would anyone else be kind enough to click and report if you can repro the problem? Thanks.
