I've got this random reboot and loop issue on mine and its really racking me off.
HTC support haven't heard of it before apparently, but I think thats BS as the first thing the guy in the o2 store said was ok we can ship that off for you - it'll take anywhere between 5-15 WORKING days.
I was like ummm ok, can you give me a loaner? nope, we can't sorry.
Mine will reboot when its a website with heavy flash on it and ironically the navigation will cause the phone to instantly reboot and loop when it goes to display the map for the route - for those of you who have seen this reboot issue happen now and again can you try your navigation and enter a car route in and see if your's reboots?
Mine seems to be heat related for sure, and i suspect its part of that whole issue of dodgy motherboards on early models. (mine was a week after release model).
M