Just a thought, do you set the start line on track? don't know if it makes a difference but I always do. Sorry can't be of more help but mine just sort of worked from the box and I'm not just trying to rub it in 
Nope, no setting the start line as I assumed that's what having the correct .dsf file for the circuit did. Thought that defined the start/finish and the tracks sectors. Maybe that file is screwed as though it's given me lap times in those files, there are no sector times, despite it looking like there's probably 6 sectors defined for Cadwell (can't tell for sure as Circuit Tools wont display Cadwell without having any data).
Should never have flogged the DL1 that I used to have.