Touchscreen acting up weird. "Auto taps" search button

Since a day or three i'm having this very weird problem with my touchscreen, I'll try describing it as good as possible:

- Half the time it works perfectly and very smooth
- Then suddenly it gets difficult to slide/drag on the screen and it seems the touchscreen "automaticly" trys to start tapping the lower right search button/icon/softkey. Followed by of course the searchfunction popping up.
- Sometimes it even goes beserk without touching the phone at all (keeps hitting the search button).
- If i then lock my screen and unlock it, it sometimes working perfectly well for a moment.
- Also noticed when it's occuring and I try pushing the hard case just below the touchscreen it also acts up ....

Okay, so I hope i described it ok, it's al so random at the moment. I'll report more if I can.

Rom i'm using: the latest cyanogenmod9 (did full wipe etc, still same problem and no-one else reporting on the same issue).
The problem also occured in Clockworkmod recovery!!!


*edit:

Quick side-note question, I have htcdev unlock and using custom roms. Can I get my phone back to full standard/stock so I can send in my phone for warrenty? Or is my warrenty already lost by using htcdev unlock etc? What are the best steps to get full stock again? (so no htc dev unlock, no root, no clockwork recovery etc ...)

after some reading and testing it turns out to be hardware related. this thread may close, looking for some help reverting back to stockrom here: http://xdaforums.com/showthread.php?t=1595539

Thanks for letting know. was getting scared I'm the only one out there . I'm just going to try to get everything back to stock and sent it too repairs aswell (since I don't have a choice at all ...)