AHA!! I've been wondering about that too. I bought 3 NIC's for our office based on the RTL8139 (a and b versions) and tried to plug them into several of our puters to upgrade from 10bT to 10/100. I had problems with the super socket 7 mobos based on the via chipset. I had no problem, however, installing the NIC on a newer MSI 6330 mobo w/a via chipset. Anyone else know something more definite?