There's lots of things it could be - a search of "remote client" or something like that will kick up a ton of stuff on the forums here. Offhand, if you're using Ghost 7.5, it won't Remote Install in a Workgroup, it has to be a Domain. I think since Ghost 8, that restriction went away.
Otherwise, the usual suspects - filesharing is on, remote registry service is on, simple filesharing is off, etc.
On your 2003 system, open up a terminal window, and just see if you can "net use Z: \\mytargetremoteclient\c$" and see if that works. Give it the same credentials as you entered into the Console when doing the remote install. If that basic net use doesn't work, then the Ghost console won't work for you either. It's a cheap, easy check.
PH