How to recover contacts from Exchange 2007

All users in our company are using outlook 2003 to connect to the Exchange 2007 no .pst on their hard drive it's all saved on the exchange. No "use cache exchange mode".
I just recently applied a new windows xp sp3 image(Acronis) on 6 machines. They are using roaming profiles so I also had to wipe out their old profile on the server and put a new one. Out of those 6 machines only 2 had their contacts missing in outlook but they still had their emails.
How is it possible that their contacts were wiped out and still have their emails if I'm assuming their mailbox is corrupt?

We are using symantec backup exec 12 32-bit version. Makes full backups of exchange no GRT(enables to restore individual mailboxes), and flush committed logs.
Is there a way to recover contacts from exchange 2007 using the exchange shell or some other method?