Authentication issue

I hope that I am posting this in the right place. Right now our
organization is having a problem wherein some machines, after having a
user login to the novell client, are not being authenticated to the
bordermanager server. When these users attempt to access internet
resources, they are redirected to a bordermanager logon screen within the
browser. Logging in through this screen only sends the user right back to
the login screen. I noticed that the bordermanager server is not showing
in the novell server listing on these client machines. It is only machine
specific - users seem able to login to other (unaffected) machines without
issue. Is there something I can do to these machines to help them
authenticate to bordermanager again?

I am sorry if this description seems vague. I am somewhat new to this.

Thanks,

David