Phone says Activesync is not 4.5

[scidmail]

I'm having a problem with my husband's Diamond. Initially it did a full sync, no problem. Then it started saying that Activsync on the pc was not 4.5. I did a repair on Activesync, no help. I uninstalled and reinstalled Activesync, and yes it's version 4.5 build 5096. The phone still says that the computer does not have Activesync 4.5 so it won't sync. I'm using the stock Sprint Rom and very few tweaks. It has Diamond Tweak installed. I did the reg edit for battery polling. Not much else. My phone is the one with the tweaks. He doesn't care, so it's really pretty close to stock. His computer has Windows XP Media Center Edition and Outlook 2002. Would a newer version of Outlook make a difference. I mean it did sync once. I hate going with a hard reboot of the phone unless I know that'll fix the problem. Anyone else ever had this problem and if so, how did you fix it?

Barb