If you've got a Warp, you may have noticed that the soft key lights seem to have a mind of their own. They light up sometimes when you don't expect/need it, and other times stay off when you when they on. Many early reviewers have mentioned this as a problem. The lights appear to be controlled by the proximity detector. Hopefully a future update will adjust the algorithm so they light up more predictably, but in the meantime, you can turn them on anytime you want (assuming your phone is on and unlocked) by covering the area to the immediate left of the earpiece (the silver, perforated thing at the top middle of the screen) with a finger or thumb. They should light up almost immediately when you do so.