Ok I tried it 
I deleted all time up to a couple of measures before the song but the glitch remains.
Thankfully Control Z restored things back to the work around.

Hey Glenn,

Try this:
Copy and past all the clips into a new/fresh project.
Does the delay problem persist?

Never done that before for a whole song.
I highlighted everything in the trax pane. (Midi and all)
Opened new
Edit paste into trax pane
A bit of a mess due to midi going into audio trax and audio into midi etc.
But I'm not getting the delay!!
Just need to learn how to copy from one song to another.
It would need the synths and drum trax all pre-setup I guess?
Doesn't work that well with midi trax I guess.

Hi Glenn,
 
You could also try saving all the tracks as a Track Template... then import that Track Template into a new/fresh project.