What did you do?
Did you reinstall suse 10.3, or the nvidia driver and why? Did you install the nvidia driver from here?
If that is not the case, try nvidias procedure and look at the posts referenced at the bottom of this thread and those at the bottom of this.
I assume that the card is not defect. Have you tried it with any live-cds of the latest distros, openSUSE 11.0, Ubuntu 8.10, Fedora 10?
512MB of RAM will work, but a bit more would make everything
quicker, that is if it won't cost you too much money.
Is there any reason why you haven't installed openSUSE 11.1, not that an updated version of 10.3 shouldn't work.