haunting network cards

I have a box under my care that has multi nics in it, and it exhibits
the following amusing behaviour

state: eth0 up, eth1 down
ping <eth1-ip> --> timeout
ifconfig eth1 ....
ping <eth1-ip> --> ping ping ping....
ifconfig eth1 down
ping <eth1-ip> --> ping ping ping....
ifconfig -> lo + eth0 up, no eth1

In fact, the pinging will continue (afaik) until reboot or eth1 is
ifconfig'd differently? I wish my bank account had that feature
"empty but they bank says money's there."

kernel 2.2.19

Ideas?

TIA,

David