Based on a thread at the Google Code site, some of those using Android 4.2.x on the Google Nexus 4
or the Google Nexus 7
are experiencing a problem with Wi-Fi connectivity on the these devices. Starting in November and running to February 1st, there have been complaints about Wi-Fi just cutting off and not working despite normal signal strength. The connection is lost
and no syncing is possible. The problem is known as issue 40065.
An XDA forum thread called "Wi-Fi network connectivity issues and a possible fix," started at the end of 2012 detailed a workaround for the Wi-Fi problem with the Google Nexus 4. Just before closing the Google Code thread on February 1st, Google came to the conclusion that some of the issues causing the problem with Wi-Fi had been identified, including scan failures that occurred with some routers. Other issues deal with Channel selection for non US regulatory domain
and ARP filtering.
Google said it was still investigating, and that fixes would go out
although it was not known when this would happen.
If the problem is happening to your Google Nexus 4 or Google Nexus 7, you can try the fix from XDA. Or, you can continue to wait for the solution from Google. The Mountain View based company has never brought the issue public, but as long as they take care of the problem like they say they will, should it matter?