Thanks for all the advice guys.

Side the problem started above, I've been getting by through resetting the transmission as the post above. It is progressively getting worse however, with jolty changes to 1st and 2nd and random changing up/down when braking / accelerating sending the revs all over the place!

Going to book it in this week to get looked at, problem is it's not the best time for me financially to start looking at swapping parts around so want to have an idea on what to ask for before I pop in.

I notice a few of you mentioned flushing the tranny fluid but I have also read a similar problem being caused by a faulty harness in my model.

Do you guys know what would be the sensible thing to look at first before I get ripped apart by a garage for needless work?

Cheers again