As you say connecting to a game is no problem, just hosting. I don't have any odd setup, just one network card and a dialup connection to my ISP. No connection sharing and no firewalls, just a local TCP/IP net.
I have however found one workaround solution:
When running Windows 2000 I can deactivate the LAN. Then I get the dialup connection IP from my ISP when starting SPWaw and can host a game. Fortunately SPWaw works excellent on W2K
I don't think deactivating the LAN is possible in Windows 9X except for uninstalling the LAN network or protocol.
Stahler