Power phone off
Slide keyboard open
Press and hold Power+Menu button (on keyboard) until "Droid Eye" comes up
Phone should say "Safe Mode" in the bottom left hand corner
Use the phone in Safe Mode for a little bit. In Safe Mode, the phone just loads the core processes and none of the 3rd party apps. Usually if you have a shortcut to a 3rd party app, it will stay there and might open, but usually you get a Force Close error. None of the 3rd party apps will load in the apps list.
If you still have that problem in Safe Mode, I would say it should be exchanged. If you don't have that problem, look at your 3rd party apps and see if any of those apps could interfere with the keyboard.
And when you have this problem, is it in a certain app? I keep alot of SMS and sometimes, when I get a text, unlock the phone and go to type, it's frozen (atleast that was on 2.0, haven't experienced that yet on 2.0.1). If you tap in the text field, it just "blinks" and doesn't bring up the keyboard and if you wait a few seconds, you get the Force Close or Wait option. I click Wait and it seems to work right after that. I just wanted to see if there was a certain time when your keyboard isn't coming up and if you were tapping on the text box to try to bring it up.