I tried changing buffers and all that. It did not help. I changed both in SONAR and in my driver, nothing. I am using a RME FireFace UFX with the latest ASIO driver.
Craig suggested updating drivers on my computer, especially graphic drivers. This was on another matter, but it might be something worth trying for this as well. I think I will give that a shot.
I went to try out Vocal Sync again, with both new and old projects and I am consistently getting the same problem no matter what I do,