I had that problem as well however i modded the zaurusd files to turn off the backlight rather than turn off the device when i close the case so when i get this problem i close the lid and reopen and it automatically fixes the problem
the only problem i have is with the power button working while the lid is closed, i have turned it on a couple of times when putting it in my pocket and not noticed till hours latter (thats why i carry a spare batt pack at all times )