Finally got this card working on FC5 with help from the following link...
http://www.ubuntuforums.org/showthread.php?t=187770
You need to download the kernel sources and install them using the instructions in the link supplied by danleff above and then edit the files:
/usr/src/redhat/BUILD/kernel-2.6.16/linux-2.6.16.noarch/drivers/net/skge.c
and
/usr/src/redhat/BUILD/kernel-2.6.16/linux-2.6.16.noarch/drivers/net/sky2.c
as discussed in the above link.
the "kernel-2.6.16/linux-2.6.16.noarch/" may be different depending on the kernel version....
then recompile the kernel modules using "make modules", and install these using "make modules_install"
You may need edit /etc/modprobe.conf and make sure that the line
'alias eth? sky2' is changed to 'alias eth? skge'
Once you've done this the card should work :-)
Hope this helps someone
Will