A possible solution is to check to see if you have selected 802.3 Framing in the TCP/IP control panel. With the TCP/IP control panel open, choose User Mode in the Edit menu. If the checkbox next to "Use 802.3" is selected, deselect it by removing the "X".
It is very rare for 802.3 style addressing to be used for the Ethernet frame type. The Use 802.3 option should only be selected for a 802.3 CSMA/CD Access Method and Physical Layer Specification. IEEE 802.3, 802.4, and 802.5 define different network topologies and media access methods, or the ability of a node to physically send and receive data on a LAN.