FYI - for those who use PDANet, I was unable to use mine after upgrading to 2.1. On my PC, I closed PDANet and then reinstalled it (the most recent version). This cleared up the problem and re-installed it on my phone as well.
Apparently this is the fix for other apps as well, like Swype.
Apparently this is the fix for other apps as well, like Swype.