Workstation disappears in network places

In short, I sometimes can see my computer in My Network
Places and sometimes cannot. Details below.....

I have a network with a domain "wca.local" (server--
Microsoft Server 2003 and clients running XP). I have a
workgroup "wca_admin" (all ME computers) that I'm trying
to get rid of and add all ME computers to wca.local
domain.

I've changed the identification to wca instead of
wca_admin. I've changed the clients to not log on to
wca_admin. I've renamed the machines and check the
settings to make sure DHCP, DNS, WINS, etc were set up
correctly on ME machine. When I restart, I can log into
wca.local domain, however, my network places doesn't show
my computer in the domain. A few minutes later, it shows
my computer. Then a few minutes later, it does not show
it again. I left for a few hour hoping it would refresh
itself or something...nothing..still no show. I move to
another computer (ME added to domain) and can see the
first ME computer but not the one I'm sitting at. I can
see the server, access files on the server, install a
printer using TCP/IP, etc, but I cannot see my computer
on the network from my end or the server end (except for
a few short minutes here and there). I can ping the
server. I checked the ipcfg and it is receiving IP from
correct server and DNS, DHCP, gateway show correct things.

I read something about the IRG maybe being different, so
I checked. The Intel network card and the monitor have
the same IRQ (11). It wouldn't let me change it in system
info or installing network card manually. I didn't get to
the BIOS configurations. But I'm not sure this is my
problem anyway.

What am I missing?

Thanks in advance.
Jen