If you've recently downloaded 1.4.1, you already know one of the major improvements was the fix for the keyboard double characters.

However, if you used the superprekernal and deactivated it for the software upgrade, then reactivated, you will have reverted your phone to old 1.4.0 keyboard timing code, resulting in your keyboard double charactering again. Uninstall, go back to stock kernel and you're FINE.

Well, now you say, this stinks I can't overclock? Nope, you CAN. But you need to download the uberkernel, which can be found in its own thread here. The uberkernl wasn't available to use Verizoners prior to the new 1.4.1 release so we aren't familiar with it. Well, get to know and embrace it because it's what you'll need to enjoy overclocking without double charactering. This is as the uberkernal is built upon 1.4.1 code.