MagentaReds

The shift and numpad - doesn't actually open up a command/console window or any give you any other visual indication. You'll only know it worked once you finish typing flush when the screen goes black for a few seconds and a message appears telling you it's flushing the graphics.

On the Six Launcher main screen, there is "Options" right under the twitter/facebook/google buttons. Click that and you'll get a a screen where you with additional options you can set. In the "Additional startup parameters" field, put in "-winxp" (without the quotes) in it. What the -winxp switch does is force the game to use lower version of DirectX 9 than it normally does, which helps performance for some people without sacrificing really any graphical quality.