Wirelessly posted (htc Pocket PC: Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 8.12; MSIEMobile6.0) Sprint T7380)
Which rom are you using? If you have tried the shipped rom or you are on it now then we can eliminate a software problem.
Could there be a missing or bent pin in the ribbon connector?
Maybe the g-sensor has something to do with it.