Everyone has their own troubleshooting quick checks; here are some that you may know well, and others you haven’t tried yet. Here’re some tips on solving common Group Policy issues.
Logon/Logoff: Some policies applied only after the second logon, not after the first logon. What’s the deal?
Anything that is set to run synchronously won’t run until after the second logon. Example of this include scripts that are set to run synchronously and Software Installation policy. Note that Software Installation policy can run asynchronously also, but behaves differently in that mode.
For more on this, check out: http://grouppolicy.editme.com/ClientSideProcessing, the “Forced into Foreground” section.