Can't install Xerox WorkCentre 425 Driver - Access Denied

I have a 2 node W2003 cluster. When I try to install the Xerox Workcentre 425
driver to an exisiting printer (which was changed to this model)I get the
error "Unable to install....Access is Denied". The drivers on Xerox site are
"Microsoft Certified" and "Digitally Signed". I am logged in with my Domain
Administrator Account. I get the same error trying to add this driver to the
server itself (server properties). I tried adding a new printer and get the
same error message. There are no errors in the event logs, and no other known
issues witht he cluster.
This is our print company print cluster and I've never seen this issue with
any other driver.
Any help would be appreciated.
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David S. DeWall, CNE, MSCE
Sr Systems Administrator