SOHO Network – Can’t see each other…

I have cable internet and two computers connected via a D-Link Hub. It all worked fine once upon a time but now, neither computer can see each other unless the “Find Computer” utility is used. Without using this the drives cannot be mapped and regardless, the “other” computer is never visible in the Network Neighbourhood folder.

I am using both TCP/IP and IPX protocols and the domain names are identical. It all used to worked perfectly. (WIN 98SE two Pentium C400’s, 2 NIC’s and one hub)