I've had my MacBook for about a year and a half now and have used my Bluetooth just fine, but now every time I go to open up my Bluetooth File Exchange, the message "No Bluetooth Hardware Found" pops up. I've called apple care and did all their instructions (tests and archive install ... everything). Any other things I can do before shipping off my laptop? No store around my area ... closest one is 3 hours away.
I'm having the same problem. I've had my Macbook since Feb 2008 and the Bluetooth just started acting weird. It displays that its unavailable 24/7. I'm kind of peeved about this.
In my case, I think the heat causes the USB bus to get scrambled and that kills Bluetooth. Sometimes turning the machine off for a couple of hours will restore it. The SMC reset won't help either. I tried the SMC reset this morning with no effect. But then I turn the machine off for a while and it works now.