The only time I've had that problem is on the stock texting app. Either flash a rom like hexen or if you don't want to do that much, download a different texting app like handcent. It seems the problem is the stock texting app itself.
Edit: Actually I didn't read what phone this was for lol...I guess just try another app see what happens.
We have two T-Bolts both stock and neither of us have ever had an errant text. There was a thread on another forum awhile back about this, and after many people started talking about it, it seemed as though it was only happening in certain regions like it was a network issue of some sort.
Possibly. It is a little annoying when someone posts up about a possible resolution to a very common and well-documented issue that effects several models of Android phones, to the extent that it made the news awhile back... and instead of being helpful or adding insight, saying "I never had that problem"...
Then don't post, as it doesn't pertain to you. By posting that you don't have the problem, it is almost an implication that the issue isn't and issue or something, when we all know that it is. It's like the reboot issue that has been plauging many Android phones for over a year now. Might not impact your particular phone, but a lot of phones do suffer from spontaneous reboots, that even HTC and VZW have admitted to the problem and said that they are working on it.
I guess my point is simply, what was your point? He obviously has the issue, as do many people. So no offense, but who cares if you don't have it? How does that help or impact the people that clearly do?