My Droid X screen will go dark after I make or recieve a phone call. I have to tilt or shake the phone to get the screen to come back on. This only started happening when I updated to 2.2. The #1 key on dialer pad does not work all the time after the screen comes back on. I don't see a time out feature for the screen while on calls. I have the regular time out feature set for 2 minutes.
Be very suspicious of the 2.2 automatic updating feature from The Market. I've had black screens and temporary bricking when downloads are being installed... and with automatic updating, you have no control over when this happens nor how many are downloaded and installed at one time.
You can stop automatic downloading of app updates by going to Market > Menu > Applications > touch each one installed and uncheck the automatic update feature.