After my Droid was upgraded to Froyo 2.2 (build FRG01B) Kernel -188.8.131.52-g103d848 - activesync stopped working on my phone. I checked this with the default email app as well as Touchdown. In checking the Android forums, I found that this was a common issue with a previous Froyo 2.2 build.
I checked with my sysadmin at work and nothing has changed on the server side. Is there a fix for this problem?