If you are finding that you don't have access to mapped drives from your admin token try the following. When running as a protected admin you have two tokens and this key will maintain the connection for both tokes (that is my understanding anyway). It can also help to clear up issues with Login scripts.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
EnableLinkedConnections =(dword)1
Also of use is the "'Group Policy Scripts can fail due to User Account Control" section of this doc.
http://technet2.microsoft.com/WindowsVista/en/library/5ae8da2a-878e-48db-a3c1-4be6ac7cf7631033.mspx?mfr=true
I will be posting more information on this soon.