I’ve seen this happen recently at my job and it actually happened to me directly. Being in Support I have to be apart of many groups. While I was setting up a new machine I noticed none of the Group Policies were applying and certain drives I normally access were now throwing a ‘Access Denied’ error. After discussing it with some colleagues we determined I was a member of too many groups. Increasing the default Token Size to 48000 was recommended. This is a very simple fix and we decided to apply it to our default machine policy for our Domain.
Data type: REG_DWORD
If you are having symptoms where your group policy is not applying or a group membership isn’t taking effect try this out.
To learn more about this check out this Microsoft Article: http://support.microsoft.com/kb/327825