[mythtv] [patch] couple of fixes for vsync

[Ed Wildgoose]

> BTW. does anyone have a nice set of mode lines and Myth GUI/Video 
> screen sizes to use? I have just been running the system at 800x600 
> but the bars around the screen are starting to annoy me.


I don't know about the pundit, but my nvidia card only works at 720x576 
(pal land).  You can generate such a 50hz modeline with gtf.

If you are in ntsc land then you can still do the same, but I would have 
thought that 640x480 at 60hz was already the best output resolution for you?