I don't see this when typing mail or texts. I do see an odd behavior when using Google in a browser. It's as if Google takes the first letter I type, auto searches on it and decides it's found a result, dropping the keyboard off the screen. That's incredibly frustrating. I don't even know how that could happen. That's the only thing I've experienced that sounds remotely like your problem.
I am having the same issues as todd DroidX. Everytime i press the space bar my keyboard goes away. Is there a fix for this? It is really frustrating.
TEMP FIX from Verizon-Go to your settings, language & keyboard, multi-touch settings, uncheck the "next word prediction" and this will fix the issue with the keyboard going away when pressing the space bar.