One of the perks of owing a Nexus phone is that usually you’re the first in line for software updates, especially when they come from Google. The downside to this is that you’re also usually the first one to receive all the new problems that come with these new software updates. And while Galaxy Nexus has certainly had its fair share of problems, the latest Android 4.0.4 updates adds something new to that list. Users who have updated to this version are reporting signal loss when their phone goes into sleep.
The reason behind the issue is not known yet, but it happens when the phone enters sleep mode and CPU goes into idle mode. As soon as you turn the screen on the signals come back, and so do the text messages and voice mails that couldn’t before because your phone didn’t have a network signal. There’s no easy turn around to this problem. You can revert back to 4.0.3 or 4.0.2 or you can root your phone, install setCPU and increase the idle clock speed of your CPU from ~300Mhz to ~600Mhz. The later of the two solutions will dramatically reduce your battery life and is not really recommended.
So any one having this issue will have to revert back to 4.0.2 until Google finds a solution to this problem.