I noticed that my personal account did not work on my iPod with ActiveSync, but my test account worked ok. I did some checking and came across an article that said that ActiveSync does not work if the user is in the Domain Admins group. ExRCA fails as well with the error:
ExRCA is attempting the FolderSync command on the Exchange ActiveSync session. The test of the FolderSync command failed. Additional Details Exchange ActiveSync returned an HTTP 500 response. Has anyone else encountered this problem?