From Dwayne D'Souza:
THERE IS CURRENTLY A CRASHING BUG WHEN DOING A FULL SYNC WHICH AFFECTS ALL IPHONES RUNNING 3.1.2 FIRMWARE (DOES NOT AFFECT LOWER VERSIONS). I AM LOOKING INTO THIS AND HOPE TO RELEASE A FIX ASAP. IN THE MEANTIME YOU CAN MANUALLY SYNC YOUR CONTACTS BY CLICKING ON THE SMALL BLUE SYNC ICON NEXT TO EACH INDIVIDUAL CONTACT.
Sync photos for your iPhone contacts with your Facebook contacts. Shows your friends latest Facebook profile photo when they call you!
Intelligently matches your iPhone contacts with your Facebook contacts using a sophisticated matching algorithm combined with a database of nicknames. Simply load up the app and start syncing out of the box.
Saves your syncing preferences so next time you can update all your contact photos in one click.