[TIGER02]

Ok two things to try let me know how it goes, still probably wanna back up your data incase u just decide to take it back and let them switch it out. Is the light blinking or constantly on. have you tried setting it in flight or airplane mode, turns off all radio including bt and wifi. If that doesnt work you might want to take your battery out for a lil bit then put it back in.

About the active sync when you plug it in to your computer does it recognize it as a htc device or mobile device, that said try unchecking "enable advanced network functionality" its been known to cause havoc with a ton of devices, and then connect to active sync. Also u might want to try plugging it in a different usb port on the computer, most have two or more.