hi, i have a 21" flat crt monitor, its a Dell Trinitron, i put it to 100mhz and its reduced it a bit but not much, but every like 20 seconds everything shakes like crazy and goes slightly blurred then goes back to normal then does it again and so on, any reason for this? when i try diff resolutions instead of shakin really fast so its blurred it still shakes but like its shivering , its quite annoying lol