sounds like it is not a wins issue,

If you can't reach a DC, you can't authenticate. (Well, that's not *strictly* true. You might be able to get somewhere with locally cached credentials).

DNS, DNS, DNS. First port of call when problems occur.

WINS is irrelevant in an all-W2K environment.

AD times out after 20 minutes

Horrendously vague. What do you actually mean here? Do you mean sessions to a server time out after 20 minutes? Well, they don't. My little Samba box at work is merrily connected to the fileserver (via SMBFS) for weeks at a time.

sounds like some aging issue. Is there any polling involved?

Aging of what? Passwords? You'd be prompted to change it. Polling? I don't understand.

Then Barry needs to frame that correctly - you'll never get an error message that says "Active Directory has timed out your foo".

As it stands, "Active Directory timed out" is a meaningless statement.