ok, specifics..
you upgraded from 2.4.22 to 2.6.0
your using ? ethernet card
your runninx ? distro.
you have tried ?
do you mean /dev/eth0 is missing,
or that it won't initialize properly?
have you tried looking for info from these commands
lspci
pnpdump
lsmod
dmesg
each with a manual page...
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