Handcent backup took too long for me. Since then, I have used My Backup Pro, which has done a fantastic job of restoring my 6700 messages with time stamp intact. Try giving it a shot.
EDIT: Just kidding. Sorry kiddos. Next time I reflash, I'll see if Handcent restore works.
Sent from my DROID BIONIC
Current Device: Verizon Samsung Galaxy Note II (Rooted!) + Amazong Kindle Fire (CM10)
Devices currently crying in a corner: Samsung Galaxy Nexus - Motorola Droid Bionic - HP Touchpad - Nook Color