Freezing and Rebooting

[mtbhrd]

My Bionic has been freezing during normal operating and rebooting itself.  Sometimes, while using the phone, a coupling actions will be very slow, then it freezes, sometimes it freezes right away.  It reboots itself after 20 seconds or so after freezing.

This has been happening on 2.3 gingerbread, hoping it would be fixed with 4.1 ICS, but it is still happening on ICS.  I have tried factory resetting multiple times, and it froze even right after resetting, without any new apps installed.  I also can't pin it to any particular app.

I'm hoping to get a replacement, because I imagine this is a hardware problem.  Is this easiest to do in store, or go through the call centers?