NT User can't access share

[Jeff Newton]

Folks,

A remote admin is trying to add a contractor account to our NT
domain with limited rights.  Unfortunately, everytime the contractor
account is removed from the DomainUsers group, the contractor 
encounters the following:

\\nt-nfs-md\IPC$

and the infamous invalid password.  Once the user is re-added to the
DomainUsers group, they can access the share fine.

My question is what permissions must the remote admin give this user
to be able to access the IPC$ share? 

Any helpful suggestions would be appreciated.

Cheers,

----
Jeff Newton
Unix Systems Administrator
PMC-Sierra Inc.