I have a droid bionic and i have the same ir light one of the reason the ir light comes on is if you have your (In-Pocket Detection) turned on and then it only turns on if you phone is vertical some how its used when your phone is put in your pocket it uses the ir to turn off the screen hope that answers your question
What if you want the screen on in your pocket so that your pants can watch their favorite show? So selfish to just ignore their needs.
What is best in life? "To crush your enemies, to see them driven before you, and to hear the lamentations of their women."