I got the same problem as discussed here: http://social.microsoft.com/Forums/en-US/windowsmobileactivesync/thread/0cf982f7-c187-41ba-b51d-6e8cf48e63ca.
I synced my phone to my PC and all my contacts got deleted.
I was really pissed off. I spent a lot of time searching online trying to restore my lost contacts.
“completely deleted from the phone, they were just made unavailable”. I searched through pim.vol. I did see some old contacts information. But it seems most of them were damaged.
I tried the perl parser from http://www.tech-archive.net/Archive/PocketPC/microsoft.public.pocketpc.developer/2007-10/msg00266.html to read information from pim.vol. I didn’t get lost contacts back.
I also tried Pocket dbExplorer 3.1 from http://www.phatware.com/index.php?q=product/details/dbexplorer, as described here: http://forum.xda-developers.com/showthread.php?t=315545. It just confirmed the lost information was just lost.
So I have to give up.
From this, I learned some lessons to backup PIM.
1. backup pim.vol at root
2. use PPCPimBackup from http://www.dotfred.net/.
3. use SKTools from http://www.s-k-tools.com/, which has a lot of features. It can backup PIM, SIM card and contacts databases etc. PIM seems to be only for phone memory. Database backup for contacts databases seems to be for both phone and SIM card contacts.
4. use dbExplorer. Export or import .csv database from or to pim.vol.
5. use JeyoMobileCompanion.
If you want to backup all PIM, 1 and 2 should be the best.