When I go into the advanced tab, there are 8 different properties that can be altered.
Early Tx Threshhold
Link Down Power Saving
Link Speed/Duplex Mode
Network Address
Recieve Buffer Size
Wake Up on ARP/PING
Wake up on Link Change
Wake Up using APM Mode

I set the Link Speed/Duplex Mode to "10 Half Mode".
Is that what you are talking about?