Sorry if my question has been beaten into the ground already, I searched for similar problems but nothing has panned out.

I have a FC4 box set up running kernel 2.6.11 on my local lan. I use it mainly for outside ssh file transfers and as local storage for windows clients using samba. I wanted to upgrade to gigabit so I bought a dlink DGE-530T and installed it using the sk98lin module through the provided install.sh script as eth1. It installed fine but will not connect to the network. I can ping the IP I assigned the card and can ping the router but thats it. The other nic (eth0) is a linksys 10/100 card.

Sooo, going on this I set eth1 as trusted in selinux and set Firestarter to use eth1 for internet and lan connections, restarted the network with 'service network restart' then brought down eth0 with 'ifconfig eth0 down' then pulled the cable from eth0 and plugged into eth1. Again, I can ping the card's address and the router but nothing else. When I try to ping another machine on the network it returns that it is unavailable, but the IP it says the ping was sent from is the IP attached to eth0. Thinking something is still blocking it firewall wise I dumped the rules with 'iptables -F'. Same results.

I read that there are problems with the sk98lin module with this card and many people had success with the skge module. The only way to get the skge is to udate the kernel to 2.6.17. I tried this but the kernel upgrade hosed x-windows and a few other things. Back to kernel 2.6.11.

After much playing around with a test box, I got the card to finally work (once with sk98lin and once with skge) only to find out my network transfer speeds from the windows machines to the samba shares are still 100MBit from either driver!! Copying from the samba shares to the windows machines is much closer to expected GBit speed. At least its kinda working! ethtool shows the card running at 1000M, the other machines on network are confirmed to run at gigabit speeds and the switch is as well.

At this point I need help to set the card up under kernel 2.6.11 using sk98lin and get the network issues worked out with the other card or how to repair everything else once the kernel is upgraded to 2.6.17.

My applogies for the long post.

Oooook, let's staart from the beginning.
First sk98lin is mostly used for Marvell Technology chipset cards these days. You didn't mention what your network card actually is, so I will assume you are using a Marvell. Consider posting the output of "lspci" here, so that we can know.

These cards are very good,but as they are very recent (~1 years old?) drivers in old kernel is unable to handle them correctly. So you will get an ip address but you will be unable to communicate then.
Now, if you want/need to use these card with old (let's say prior to 2.6.17) kernel, you have to download a patch from marvell website, to patch you kernel and to recompile it. However, if you are not familiar with linux, I don't recommend to try that.
The "easy" solution would be to update your kernel, using yum apt-get, or whatever your favorite tool is. Any kernel >= 2.6.17 should be able to handle this card, HOWEVER, the driver name has changed and is now called "sky2". You will need to make sure your system is loading the "sky2" drivers instead of the old, possibly buggy, sk98lin.
Of course, updating without network would be a bit tricky. Again, the easy solution would be to find an old PCMCIA/Cardbus card you could use.
If you don't have such card and don't know anyone that does, another solution would be to burn the FC5 or FC6-beta cdrom, so that you can upgrade your system using RPMs on these cdrom.
You could also download RPMs you need one by one and transfert them to your computer using, let's say, an usb key. The only RPM you need is the one relative to the kernel (I don't remember how fedora call it, probably linux-kernel-2.6.XX, linux-2.6.XX or kernel-2.6.XX... you will need to do some research about it) but I suspect it to have several dependent RPMs that you will need to install as well.
Of course, the lazy but very easy solution would be to reinstall a new system using a more recent version of fedora.


Now about your Selinux/Firestarter... As I said, at my opinion, the problem is about your network card drivers, so these tools can't do anything about it.

I hope this help.