(I don't work for Nokia, and besides, nobody knows your real names);

Has the 770 been dropped?
Screen protector?
Exposed to very hot or very cold conditions?
Handled roughly(ie pressing too hard)?
Twisted?

Sounds to me like the layers of the screen might be separated a little bit and this is causing it to be less sensitive/not working entirely. Wondering what the common thread is so's I don't hoop mine (stuck in Canada without a warranty because of that fact (I think)).