That sounds like a warranty issue.
Sent from my Galaxy Nexus using Xparent Cyan Tapatalk
No, plenty of people have this problem. I did too for a while, seemed to have stopped when I installed Axiom.
Its supposed to be fixed in 4.0.4 though if you feel like flashing that.
Sent from my Galaxy Nexus using DroidForums
When mine did it it'd be after about.. 20minutes or so after talking to my girlfriend where I'd find myself talking to myself until she goes, "Hello.." and I have to hang up and call back.