Hello Brooks,
May I have the adclient version that is in use on this system?
Please run "adinfo -v" to get this information.
Also can you please check to see if the user with the problem is a part of many more AD groups than users that are not experiencing the issue?
Please run "adquery user -A USERNAME" to get this information ( Both Local and AD group memberships will be at the bottom).
Thank you,
JeffW