So I have got these really weird latency issue with midi, and with ONE project only...previous to today no probs and nothing has changed on the system and it is setup exactly the same for all projects...this was a previously saved project.
 
So the issue? When I boot the system and then start Sonar, load the project insert a soft synth no probs, latency is as it always is. However the minute I hit record, it introduces this (about) 8ms lag...this then stays with the project on this track no matter how many times I remove the vst and re-load it, delete tracks, save the project, delete the project. Whatever. I have to close down the PC and restart.
 
And the weird thing? it ONLY happens with one project...all others are fine???? I would really welcome some ideas here. Now remember NOTHING at all is being changed with the PC system or Sonar preferences and setup, nothing!
 
Oh and I thought, oh well, just put up with it for recording the track and playback will be fine...but no, the latency is also evident when the track is being played back.

Mostly likely this is due to having a plugin in the project that requires Plugin Delay Compensation, because it uses an additional internal audio buffer to do lookahead processing. Common offenders are convolution reverbs like Perfect Space. The PDC [override] button in the Mix module can be used to temporarily disable PDC on a track that you want to record/rehearse if the delay-inducing plugin isn't on that track or on a downstream bus, but it's best to just avoid using such plugins during the tracking phase of a project.
 
PDC is recalculated/reset when you run the transport which is why you might not encounter it until you start recording.

thanks Brundlefly...I did not know that. I will investigate as it may be I have something like that in the project but didn't realise it.