Exchange log file directory error “access is denied”

Need to enable message tracking in Exchange and the directory dialog box has the following error.

Access is denied.

Facility: Win32
ID no: c0070005
Microsoft Exchange Management

The administrator account has full access to the this directory D:\Program Files\Exchsrvr\xxxxx.log and it still refuses to let me make the change.

Running:
Exchange 2003 sp2
Windows Server 2003 sp2

Any ideas??

Thanks in advance!

John