Multiple SMS over different ROMs

My phone will send texts messages repeatedly, sometimes 5 or 6 times to people. I've read about people having the same issue with handcent, or chomp, or whatever, and their issue seems to always be one app. I have tried handcent and chomp, trying to fix this issue. It has followed me to every ROM (UD, Cyanogen, Zeusdroid) and has even affected the native messager in the Sense UI ROM. So the issue can't simply be with one app, but rather my phone. I got a replacement phone (for an unrelated headphone jack issue), rerooted, and have still had the same issue on different apps and ROMs. Can anyone imagine what could be causing this issue? I don't like the native droid messager, and I like the Sense UI ROM, but this is really annoying people I text.

Strange, I've used a bunch of different ROMs and that has never happened. If you text people with the native app, does it do it then?