So, latest HTC Desire Z update (to 2.3.3) seems to cause weird issues on the 'real' keyboard, and the behaviour is intermittent.
For example, you'll be typing an SMS, and when you press certain keys, other apps will open. Which is annoying. Curiously, rebooting the phone solves it, until a few days later and it'll start doing it again.
First off, it's not in the Settings->Keyboard shortcuts preferences!
Look in Settings->Applications, and choose 'Quick Launch'. A handful of shortcuts are defined - b, e, g and s - by default. You can clear the assigned ones by long press on the row. Solved...
