Linksys EtherFast error - eth0: lost link beat

["Randy W. Sims" <RandyS@ThePierianSpring.org>]

I've got an old Toshiba Satellite 2655XDVD that I installed Debian 3.0r1
on. It keeps giving error messages:

eth0: lost link beat
eth0: found link beat
eth0: autonegotiation complete: 100baseT-HD selected

[repeat...]

It's connected to a network via a Linksys PCMLM56 EtherFast 10/100+56K
Modem PC Card. I'm a complete idiot when it comes to configuring
hardware; Can someone point me in the right direction?

I already followed the directions on the Linksys support pages, adding 
the following to /etc/pcmcia/config:

card "Linksys EtherFast LANmodem 56K"
version "Linksys", "EtherFast 10&100 + 56K PC Card (PCMLM56)"
bind "pcnet_cs", "serial_cs"

Thanks,
Randy.