I think the video card (chipset), is a little bit old, and there were problems with the drivers on older nvidia cards a few months ago. Those driver problems may have been fixed in the latest versions, so, I would try one of the recent sabayon releases at: http://torrents.sabayon.org
I like kde so I would probably get this one: http://torrents.sabayon.org/file?info_h ... %16H%7B%07
If you prefer gnome, or a lightweight DE, they are right there too.
If they run as a live dvd, you could install it. If it still works good after the installation, do an upgrade, and that might be where the driver problem shows up. It would require you to install an older nvidia driver...not too difficult. But, I think it will survive the upgrade with no problem.