I've updated cm from 10.0.0 to 10.1.2, and after updating the gapps too, several things are broken, including Gmail and Drive.
Now, Google Play lists them at "updatable", but it is broken and refuses to update any app, reporting
Error retrieving information from server. [RPC:S-5:AEC-0].
Some google services apparently work (Contacts, Calendar), so I guess it's no login problem.
I've tried wiping data of a few related apps, but it didn't help.