Hi Kartik,
I just got my HTC Desire (1st version, not HD) back from 1 month in HTC Customer Support in Singapore (bought in S'pore airport). They replaced the entire motherboard (no charge - under warranty)m due to overheating and repeated spontaneous crashing, often crashing several times before the reboot cycle was complete. Others have reported same M'board problem. Now having premature call cutoff problems, not yet sure if it the phone, but will test alternative SIM card for a few days to see the pattern. Not a happy customer! Kim