Midi Help

I am using Sonar X1 and I have a Yamaha Motif I am using along with it.
 
When I play back (pushing the space bar) during midi recordings I get a bouncing or skipping effect, when I look at the seconds counter for instance it will stop for a split milisecond on 2 then just jump to 4 skipping 3, it does this througout the entire play back, my playback is not smooth.
 
 I thought is was the way I had the keyboard hookup up, so I turned off the keyboard and opend up a new version of sonar just to test it, and the first thing I did was hit the space bar with no tracks recorded either midi or audio, and as the line goes across the screen you can see it bouncing/pausing a skipping across.
 
I have tried everything and no luck, if anyone can help me I would really appreaciate it.
 
I am running an AMD quad core porcessor, and 4 Gigs of ram my computer is fairly new and I am sure it more than powerfull to run.
 
 Thank you.

Thanks, I had already tired that I put 128/500 and not luck.

Yeah I changed the right ones, the playback and recording I/O buffers I did not change they are both set at 256.

Thanks for your help, I have tried searching for a few days now, not any luck yet. I also thought it may be the Motif, but I totaly disconected it from my system, opend up sonar and hit the space bar with nothing recorded and it still does not run smooth.

The audio runs smooth but with a lot of crackling, the midi does not run smooth.

The pause/break is off, the jerking in very minor but enough to make the midi go off when it triggers my Motif. I have messed with the cards buffer settings and nothing seems to fix that issue.