Thanks for your help guys.
Hugh - I have the latest version of X3 including both SP's and hot fixes. I can't see any other download which might address this issue.
Ariel - appreciate your advice. I would like Cutting Manager 2 to load up when I send the job to Cut/Plot though because of the different layer/colour options I can choose to cut, along with sizing, orientation etc.
As a temporary workaround I've been exporting my work as AI then sending to Cutting Manager using Illustrator CS2 but I would rather not have to take this extra step and simply do everthing in X3.