Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8A306 Safari/6531.22.7)
You checked to see if your rotation lock is enabled right?
Is so, rotate the phone to the upside down orientation, then back. My old 3G would get stuck sometimes and that would free it up.