Originally Posted by JSanders
You are very likely accidentally hitting the "k" key (shortcut to lock the keyboard) upon holstering (if it only happens sporadically. Are you placing your 8800 in your holster face OUT or face IN? Try it face IN, if that is the problem.
You can also check your Options > Security > General Settings and see if under LOCK HANDHELD UPON HOLSTERING is Yes or No.
Well, in terms of the settings, its set to No (not lock upon holstering). As for the K key, i've got it set to dial from my home screen, so hitting k just brings up the phone app...