I run a win 98 and win xp simultaneously using a broadband router. Just recently I set up a home network with them, using the win xp CD wizard to do so...IP addresses assigned automatically, as well as MSHome work group, NetBios enabled, file and printer sharing etc.
I can ping fine between the two using the assigned IP addresses, and the win 98 system can see the other computer and access its shared docs folder just fine. However, my win xp computer cannot see the win 98 or access its shared folder (the one with the files I really want to transfer.)
I've tried typing into my XP run box \\xxx.xxx.xxx.xxx(IP address win 98)\shared docs... as well as other similar commands, and just wound up with "The network path was not found"
its a common issue when using different OS versions.... you could try installing a VPN like HAMACHI (free) and that will happily allow shared folder access to work....I had similar issues trying to share between XP and Vista.