holy crap. I thought I checked that already. Somehow mine was set to 5 minutes. I set it to 30 seconds and were gravy. I feel like such an idiot. Thanks a lot.
Same thing with me - backlight is set to 30secs and standby 1 min. sometimes it just goes off without dimming and most of the time it dimms but its definitely a problem with the 3.16. I have the 3.16 unofficial with only HTC home installed