I'm using Producer 7, my PC runs Win 7, loads of memory. Recording Midi from my Motif XS  through USB.
Recording is fine but when I play it back the timeline moves jerkily stopping for up to 1 sec at a time then catches up by playing fast. I've tried pressing the Pause/Break button and I've got the buffer as low as poss.
Any ideas experts?
Thanks in advance
Peter

Windows 7 64-bit?  Sonar 32 or 64-bit?
Make sure your audio device is set for ASIO mode. 

SONAR has a mode that kicks in when CPU cycles are in short supply, wherein visual components are deprecated in favor of the audio stream. The most obvious symptom is a jerky time line and lagging response to button clicks and dragging knobs and sliders during playback. 

Try bypassing effects, starting with busses, and re-enable them after you've finished tracking. You might also check your Windows task list for any processes that can be killed, e.g. OSPPSVC.EXE. If you have a network adapter in your DAW, see if disabling it doesn't fix the problem.

Guys I am most grateful to you both for your advice, I now have a smooth playback by switching to ASIO (senior moment did not spot this) and generally turning off any surplus operations
It was 32 bit Dave
Thanks again guys - you're the biZ

You might also find you get this behaviour by pressing the Pause key on your keyboard

It was 32 bit Dave

Glad to help, but with 32-bit, you're wasting more than half your RAM because 32-bit can only access 3-4GB at most. Move to 64-bit so you can use all those loads of RAM. 

I don't think there was a 64 bit version of Sonar 7 but yes hopefully he's running W7 64 bit.  I still have Sonar 7 installed on my W7 64 bit and it works fine. ( haven't used it in a year however) 

Cactus Music

I don't think there was a 64 bit version of Sonar 7...

Yes there is.

Thanks again guys for your advice
Bristol Jonesy - already had tried that (see my post)
Dave - thanks but whenever I alter something on the PC things tend to go belly up - it's all working fine now so I'll stick where I am
Regards
Peter