With respect to the 990's front panel display, I've noticed that the timout isn't honored when adjusting the volume. It will always go dark after about 3 seconds.
Initially this confused me a bit, but when I thought about it, I realized that it's a feature - and a nice one at that. I'd rather the display didn't stay on for the full timeout (in my case, 30 seconds) every time I adjust the volume during a movie. Good software anticipates your needs.
Anyway, assuming your issue is with the front panel display, try hitting just the NIGHT button and waiting. Does the display stay on for the period you've set it for?