I was looking at the HCL entry
for the Netgear FA311 and it seems that it is actually a very compatible card. One of the guys there uses the "tulip"
drivers, not the natsemi ones - have you tried tulip? You may want to see if the tulip ones work, and if they don't then please report back.
P.S Could it be possible that your current version of natsemi is having problems with some of SUSE's software or kernel?