I've been having this issue for a while now and I've found similar posts elsewhere but I have never found a solution. On any AOSP or Google Edition rom I've tried (pacrom, liquidsmooth, cyanogenmod, Danvdh's GE, etc.) I always run into the same annoying issue. My lockscreen will freeze and will not respond and I am forced to manually reboot by holding down the power button. Sometimes the screen comes and sometimes it doesn't when it freezes. Also, I think every time has been when the phone is in deep sleep (I can't remember if it was every time for sure). Most of the time, I will wake up in the morning, reach for my phone annnnnnnnd it freezes. I'm convinced it's a kernel issue but it's happened with KT kernel, CM, Chronic, and any other AOSP/GE kernel I've found to try. Also, I never have this problem with TW roms.
Sorry this is so long but this is so annoying
Btw I have an SGH-I337