Do the basic checks first: -
(A) is the crossover cable ok?
(B) are the RJ45 Connectors connected ok? Are they seated correctly in the etnernet card?
Maybe what I am saying here sounds silly. But these are many a times the things that people overlook. The number of posts about these sorts of things on this site and on the net is huge.
Next. Check out your settings. I notice that you are using the same default gateway for both the intranet and the internet card. Is that the way your ISP has told you to configure the network??
Try making the gateway for the local net the same as the IP address on the LAN of your linux machine.
I use Mandrake 9.1. It has very good hardware autodetection utilities and I find them very easy to use. I have been able to set up my LAN several times and have found the process to be slightly lengthy most of the time. If SuSE has similar hardware and LAN settings detection utilities, try them out. They may not be THE solution. But they help.
One more interesting solution I can give you as a test of your network. Its a floppy based distro called coyote linux. Go to http://www.coyotelinux.com
and get the windows based boot disk creator for coyote linux. The process of creating the disk is ridiculously simple and it works out of the box. It is intended for firewalling and routing, But the thing about it is that it will help you find out if the network is correctly configured. As coyote appears to work correctly from the word go if the settings are correct.
Hope that helped you