Greetingz!
Sounds like you're either a) not loading a module for the NIC card, or
b) you don't have compiled-in support for said NIC card.
Boot off the old kernel and do an "
lsmod | sort -u | tee -a ~/modules_old".
Boot off the new kernel and do "
lsmod | sort -u | tee -a ~/modules_new", followed by a "
diff ~/modules_old ~/modules_new"
At that point, try "
insmod modulename" and see if you get lucky.
