[Shenanigans]

I've tried running xbmc on my Mac and I am getting choppy video during faster paced scenes. Lines will show up where info is missing the video gets thrown off. I think it has to be xbmc.
I am running an early 2008 Mac Pro quad 2.8GHz with stock 2GB RAM and the 8800GT. It's a .m4v file, 843x480, h.264, 1500kbps average video with 128kbps audio. I played the same exact scene through Front Row, Quicktime, and VLC and there was no issue at all. No choppiness, no pixelation, looks perfect as it alway has. I've never had choppy playback with this computer, even with HD stuff. I ran XBMC with MenuMeters going. Even with a bunch of apps running in the background, I am still at 1200MB free of RAM and am running max 14% at any one of the CPU cores.
I don't see many video settings I could have mucked with to throw something off. Audio is set to analog. Render method for video is auto detect. Adjust refresh rate is off, software scaling is off.
Thoughts/ suggestions?

[Shenanigans]

Oh yea, I am running a DVI to HDMI cable to my 32" Samsung LCD and have the audio sent directly to my receiver.
Also tried going through my PS3 using MediaLink and the file plays through my network without issue at the same point there is choppiness with xbmc.

[althekiller]

Please see the sticky regarding posting problems in a useful manner.

[Tbtf]

turn Vertical Sync to Always. Had the same problem.

[Shenanigans]

turn Vertical Sync to Always. Had the same problem.

That did the trick. Thanks!

[newtoxbmc]

I am also facing same choppy Video in xbmc while it works fine with all other player.
I tried to find this vsync setting but unable to do so. I have onboard ATI graphics card. I am connecting 40" LCD through HDMI. Any Suggestion?

[bobo1on1]

Check Settings->Appearance->Screen.