[moisha]

This is basically what I was talking about in my post a page above. I've seen in in the past happening on both of my previous phones. The so common SOD Sleep Of Death. There is a strong believe that the cause is improperly dumped ROM. The bottom line is that flashing carefully selected one, or better yet the official one (HTC / OEM distributed) should fix the issue. Not sure if HTC or T-Mobile ever posted one for HD2 yet.