Browse the registry on the RAS client at:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards

For each numbered Sub-key, verfiy that the the ServiceName value has an entry for that service at:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services.

If it does not, delete the key at:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards\<number>