The sensor that turns the screen off in my pocket or at my cheek is suddenly turning the screen off when my thumb is within two inches of the top of the screen. It is difficult to grab the notification bar without triggering it, and holding my phone sideways is now an exercise in frustration. Is there a way to fix this? Did some update recently come out for the Galaxy Nexus (GSM)?
Z-Device test may show your sensor output: https://play.google.com/store/apps/details?id=zausan.zdevicetest
- some aftermarket display protectors may cause that
- an earlier Android release only switched the screen off via proximity sensor when held vertically. This would have prevented your described problem. (See http://www.guytechie.com/articles/2012/1/22/galaxy-nexus-slow-proximity-sensor.html). Maybe this behaviour has been reverted.
If you updated just before noticing this problem, you might have to switch back or wait for another update to fix that again. Installing a 3rd party update like Cyanogenmod9 might also fix your problem.