My Sony VPL-VW60 very suddenly lost significant brightness literally overnight--one day it was fine, even watchable with plenty of ambient light in the room to interfere, and then the next day it is totally washed out by any ambient light and not even really watchable with the room is pitch dark. I've tried adjusting all the setting in the menu to improve the brightness, but to no avail. The lamp has only 1250 hours on it; I replaced the air filter when prompted...