buttons stops working

Try removing Advanced Task Killer.

Unfortunately, only the service can solve this problem.I was told that's problem of the keyboard modul or something like that:

I have an HTC Desire Z and my menu button stopped working and it seems as if I have a dead spot on my screen.  When I try to do screen calibration for the on screen keyboard (you have to hold the phone upright in order to get the option) the "X" doesn't work.  Also when sending a text message if I have the phone held sideways the send button doesn't work.

Uninstalled everything and factory reset with no results.  Guess I'll try to find a repair shop and then I'll repost the results.  Haven't heard any good news from this blog.  :-(

I really liked this phone too.  What a drag.

Luckily my phone is still under warranty and I got the screen replaced.  Then the phone was hanging all the time after I got it back so I had to take it back again and they fixed that. But I guess when they replaced the screen they didn't do it right and I'm getting dust under my screen.
Now I have to take it back again to have them install the screen properly and that's all the way across the city.  I live in Jakarta.
I also have this new thing where the A on the keyboard doesn't work until I push it again or when I push it once I get 2 As.  Weird.  E is acting weird as well.
I'll let you know more after I get it fixed again.

Had them fix the screen while I waited and told them about the A and the E on the keyboard playing games with me but I don't think they did anything about that.  Screen is clean and I'll just learn to live with the rest.

Good luck to the rest of you.

If your buttons quit working send it to the local service center.

Hey Ryan, thanks very much for this.  I had the exact same problem and nothing I tried was working.  I tried this and it worked!  It is staying working too.

This fix would indicate some sort of hardware/connection issue.  The most odd thing though is that when the 3 buttons were not working I would find that if I shut the phone down and rebooted it would often work for the fist few seconds.  Likewise if I started the phone in 'recovery' mode (hold down the 'down volume' button and then power on), once in the mode I was able to navigate down AND up using the volume buttons.  So that would indicate a software issue!  Confused?  I am!   

Regardless, the 'fix' of pressing down hard under the menu button seemed to do the trick.  RESULT!