I have been getting duplicates from all contacts so far. Though not every message gets duplicated.
It's not only handcent... I'm using stock and receive duplicate texts. My phone also sends duplicates to other people which is probably the most annoying thing because then they get irritated. My phone also sends old texts again when the phone reboots...annoying. HELP! And I don't want to download a different messaging app, I just want the issue fixed.