Desire not syncing with Google

[Guest The Doctor]

Ok, so I have a fairly weird problem (at least, as far as I can tell, nobody else has had this problem).

My HTC Desire refuses to sync contact data to my Google account. If I edit a contact on the device, the changes wont be synced to my Google account, but also it will delete any contact I've created on the phone when it next syncs :/ But if I create/edit the contact using the GMail web interface it syncs to my device just fine :S

How can I get my sync settings to play nice?

I'm using the MoDaCo r3.1 ROM

Phil

[EDIT: This also appears to be my 1337th post :(]

Edited July 22, 2010 by The Doctor