How to enable vsync?
 

I'm running Mepis 3.3 on a Gateway 450sx4 laptop. When trying to run zsnes I get terrible screen tearing. The -w switch in zsnes doesn't help the tearing, and I think that vsync is disabled on my system. I have tried adding +vsync and -vsync to the mode lines in my XF86Config-4, but that hasn't helped. Any ideas?