Coincidently, I'm experiencing the same issue. I've had Sonar for many, many years. I rarely make any changes to my configuration. I can't remember if anything major changed in my set up recently. But here I am, pulling my hair out trying to find the root cause.
Even as I record a signal live, it appears to be tracking with time. It isn't until the recording is stopped when the image is repainted on the track approx. 1/16 ahead of the place it was originally recorded.
Need help badly. Already spent 1 hour trying to trouble shoot this.