Help! iPad calendar sync issues with Exchange server

Hello, I've googled this issue and haven't come across with any definitive answer so I'll put it up here to see if anyone have any idea(s).

iPad 3G/Wifi working fine for over a month (firmware 3.2.1) synching with MS Exchange server (only Mail account on the device), over the weekend, calendar entries have disappeared. I've deleted the mail profile and reset it up again, here's what happens, email starts to pull down, same with contacts and Calendar entries, then while Calendar App is open on Month view I can see that the appointments are also being sync then after about a minute, all the entries will just disappear, if I wait a few more minutes, the appointments will start to repopulate again then disappear again after about a minute! Email and contacts are fine, just this Calendar issue.

More background data: User is using an iMac with Entourage 2008, his EA has full email rights to his mailbox and have his email profile on Outlook 2003, both are showing correct Calendar entries on desktop, have also checked the account on OWA and it looks fine there as well.

I'm guessing a corrupt calendar entry (possibly re-occuring appointment)... Does any one have any other thoughts?

Any help would be highly appreciated.

Thanks!!!