Chances are you will need to do a clean install. Something got corrupted. Backup your data with TWRP or CWM. Whichever you prefer. I haven't installed B5 yet on my gnex. I am not really planning to either. I will install it on my Nexus 7 however.
Brought to you by the Google Galaxy Nexus. It IS better than the iPhone 5.
I got the phone into CWM. Wiped cache and davlik reflashed B5, newest version of gapps and Picasa sync gapp. All better.
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