to see what kernel and other os, cpu info type in a terminal window:
uname -a
in there will be the current running kernel. 2.6....
If you have upgraded the kernel the origional one should still be installed.
so at boot when the grub screen comes up choose the 2.6.17-10 kernel to boot off ( at the count down hit an arrow key, then down arrow to the 2.6.17-10 kernel line and hit enter)
then check if your networking is going.
