I am getting dupes on every text I receive. I wasn't before I updated to p3droid's prerooted GB update.
Could you please turn on delivery confirmation if it isn't already? That's something I did, but never made the connection that may be the key. Thanks to ELH for mentioning that. I don't think the callback number has anything to do with it since I've always had that turned off since I got my phone 6 weeks ago and was receiving multiple duplicate texts as well as sending duplicates on reboot.
edit: Now that I think about it, the delivery confirmation probably won't make difference on received texts since it's for confirmation of texts sent from your phone.