Hey, I did a search and couldn't find an instance of this happening to anyone else. So, anyway:
I use a Motorola HS820 headset (which I love) with my BB 7130 with no problems. Last night I turned my headset off (I wasn't ending a call; I was merely powering down the headset) while the Blackberry was out of the holster with the screen dark and I immediately saw the LED turn orange. I rolled the thumbwheel expecting to see the "lost connection to HS820" prompt but what I saw instead was a white screen with the spinning hourglass. The unit was in this state for about two or three minutes, then it turned itself off. A quick press of the power button brought my BB back up with no apparent side effects. Weird, huh? I will test this again today to see if I can reproduce the same results.
Another note: as a former PPC user it scares the hell out of me to see any kind of system freeze-up or unexpected reboot, but I must say that my one-month experience as a Blackberry user has been completely worry free. I wasn't even worried last night when the BB was acting weird... I was just interested in how it would turn out!