[cvsnt] Problem with cvsnt server, cvs unix client

[Ditchfield, Glen]

I hope I'm making a simple mistake. 

I have to use a particular cvsnt server from various development
environments.  I can access it using Windows tools; for instance, using a
Windows command prompt window and the cvs command-line tool that comes with
TortoiseCVS 1.2.2, this works just fine:

M:\>cvs -d :pserver:adomain\auser at aserver:/d//cvsrepos/corporate login
Logging in to :pserver:adomain\auser at aserver:2401/d//cvsrepos/corporate
CVS password: ***********

However, I can't authenticate using the cvs program from cvs-1.11.6 (not
cvsnt!) on an HP-UX machine:

[cvs]$ cvs -d ':pserver:adomain\auser at aserver:/d//cvsrepos/corporate' login
Logging in to :pserver:adomain\auser at aserver:2401/d//cvsrepos/corporate
CVS password: ***********
cvs login: authorization failed: server aserver rejected access to
/d//cvsrepos/corporate for user adomain\auser

What can I do to get access?  I'm not a CVS server administrator, so I can't
make administrative changes.