Bought in Norway.

Reboots started straight of out box.

First was when adjusting the clock. No apps installed at all, besides pre-installed ones.

Happens randomly when using any app (browser, chess, calendar, contact list, etc. even in the app list screen, and telephone screen. Sometimes instantly, sometimes after a couple of minutes.

Wi-Fi on or off. 3G on or off. SIM card installed or not. No difference.

Returned phone, but probably won't be getting any replacements before start of next year because of slow shipping times, and holiday season inc, which sucks because, despite of the annoying reboots, I quite liked the phone