Problem
When you return to the beginning of your song or start a recording, the playhead of a synchronized DAW happens to jump to far away positions or seemingly undefined positions altogether.
Cause
Some DAW do not support the negative locator positions that Synfire sends during a short pre-roll required to start playback or recording.
Solution
Insert one bar of empty pre-roll space at the beginning of your song and disable Allow Negative Locators in Synfire's sync settings on the parameter inspector. Set Global Pre-Roll (Measures) to 1 in order to make your bars numbered correctly on the time ruler. Also insert that extra bar in your DAW project.