natsemi trouble with netgear fa311 in 2.4.6

I have a NetGear FA311 pci card that uses the natsemi.c driver and have had no problems with it in all kernels 2.4.0 through 2.4.5. However with 2.4.6 (also tried 2.4.6-ac2) I am getting strange behavior. As soon as an ip is given to it (with either dhcp or manual ip) this error message keeps repeating:

eth0: Something Wicked happened! 18000

and I can't ping anything else except itself. It's always 18000. I've tried switching the card to another pci slot, checked the cables, etc. When I switch back to kernel 2.4.5 everything works perfectly.

The bootup message is: eth0: Setting full-duplex based on negotiated link capability.
And lspci shows: Ethernet controller: National Semiconductor Corporation: Unknown device 0020

The computer is a k6-2 400 with an ASUS P5A motherboard (ALi chipset)