Had my phone replaced a few weeks ago. Was a Rev C now have Rev B with 1.20 Sprint firmware. I've generally been happy but for a couple of bugs - most concerning is a "thermal lockup" condition. I'll be talking for 15-20-30 minutes on the headset with phone in belt case. Removing phone from case, it is non-responsive to any button pushes, say, to check calendar while on a call. The phone is very warm, not hot. After a minute of open air cool down, I get normal response from buttons. Anyone seen this kind of thing?