Question : Why don't I have access?

local administrators group contains domain admins group and ACL shows local Administrators group on the ACL yet my access is denied. I can open up the drive, I can attempt to open the folder, and it prompts me to grant me access.  If I view the ACL on the folder it shows the local servers administrator group on the folder and the local administrator group contains the domain admins group and I'm a member of the domain admins group.

Is this some new Windows 2008 R2 behavior?

Answer : Why don't I have access?

Please look over this link the issues seem to match.
http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Server/Windows_Server_2008/Q_24789757.html