Backlight Problem

My Treo 800w has a tendency to turn off the backlight when on for a few seconds. I can't turn the backlight on until I turned off the screen and turning it on. I have the settings to turn on backlight when screen is tapped on or a button is pushed. Also sometimes when I put the Treo to sleep, the backlight remains on with the screensaver on. I'd have to turn on the phone and re-put it to sleep for the backlight to turn off with the screensaver enabled. What's my problem?