Hi guys, I have 3 boxes running XP that network fine when I use my old 10mbit hub, but if i use a 10/100 switch set to 100mbit they cannot see each other at all. If i set the network speed manually to 10mbit then it all works once again. There is nothing wrong with the switch.. Perhaps its the cheapo network cards they are based on the realtek rtl8139 chipset.. Bugger its really got my head scratching:P Anybody have any ideas on this? Why would it work in 10mbps but not 100mbps??? All the network cards are supposedly 10/100, all use the 8139 chipset..