Ok, I'm confused. I setup a small peer-to-peer in my friend's office. 2 PC's (one running NT 4.0 and the other has Win 98) and one printer. The NT box has the printer on it and a modem. The IP configs are as follows:

NT:
IP - 192.168.0.1
Sub - 255.255.255.0
GW - 192.168.0.1

98:
IP - 192.168.0.2
Sub - 255.255.255.0
GW - 192.168.0.1

They use an account with the same name/pw on both pc's and they have drives shared. My buddy (at the suggestion of the support group of one application his business uses) upgraded his NT machine from Service Pack 3 to SP6a. This shouldn't be a big deal, I deal with SP6a at work all day long. However, now the 98 machine can see the shares on the NT box and can ping the NT box, but the NT machine can't see 98 via TCP/IP or the shares on the network (NetBui).

What gives? It's not a bad NIC or cabling or the hub because 98 can see NT just fine. But not vice versa....