Sanyo S1

Anyone else have this problem? Almost every time I try to check the time (i.e. the phone is locked so I hit the back button to turn the screen on)the screen comes up completely white. Most of the time if I just let the screen turn off on its own and try again it comes up regularly, but sometimes I have to turn the phone off and back on to get a screen. I've only had this phone for two months...