Display permanently switches off

[Guest]

I'm having a strange issue with the backlight. After a long runtime, say 100-200 hours, the display sometimes gets stuck in a permanent off state. Everything else still seems to work fine - the phone reacts to presses on the sleep button (button backlight still works), charging indicator LED works, etc. I can also access it via ADB shell and everything looks nice and peachy. Except that I can't get the display to switch on again and use it! I can't see anything special in the logcat either.

I've seen this problem with both Swedish Spring and now CyanogenMod 7.1 (nightly). What's up with that?