Hi,
 
This has just started, the now time marker is not smooth, it jumps every second or so, although the in the project tracks are playing normally don't know what I've done, can anyone help with this one please.
 
Thanks
John
 
I'm just a bit dumb today lol !!! obviously hit the pause/ break tab on my PC !!!!!

That has never happened to any one else before, at least not me 

Been there done that.
Once I even hit the "Scroll lock" and couldn't figure out why the timeline was locked