Got the exact same problem with my htc desire. Looked around and it seems to be a semi-common problem that has developed in a few peoples phones. And apparently its linked to a recent update on the phone. My only advice is what i was given- their is an update u need to download online to fix it. If that dosent work or help take it back to where u got it from and say the damn thing is faulty and ask for ur money back!! Good luck!