09-04-2013 02:37 PM
Hello elizardoz and welcome to the BlackBerry Support Community Forums.
In Contacts>Menu>Options locate this email account and ensure there's no check mark in Wireless Synchronization. Try to sync your Address Book. Does it now work?
If not, go to Options>Device>Advanced Options>Service Book and locate this email account in your list that has [SYNC] after it. Once located, hit the DEL key or Menu>Delete to remove this Service Book.
When you go back to your Address Book>Menu>Options you should now see Default. If so, now attempt to sync your Address Book. Does it work?