Most of the callers complain that my number is switched off but I never power off my handset. I tried with another number and observed the same while my HTC Desire was in front of me and powered on. At times it does connect but most of the time not. I have full bars. I was using HTC Touch Pro2 earlier at the same location for at least 10 months now. Had no issues with network. Got my HTC desire 3 days ago and have this problem ever since.