Nice one, thanks 
What DV valve should I replace it with if it does turn out to be knackered?
Can you also recommend what spark plugs / HT leads you guys run?
Cheers
Russ
This is the latest revision D type, the part number is on the side, cost around 52 quid from the dealers.
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Regarding performance, mine still felt quick but I had noticed some flat spots, Carl logged the results a few weeks back and the boost was almost half expected figures. Since changing the DV the car is awesome again, it does have a stage 1 and EVOMs though.
Edit: have a read of my thread on the Briskoda site, image of the knackered DV in post #12. You will see that mine was completely split, but afaik even a pin prick in the diaghram will affect peformance.
http://briskoda.net/forums/topic/187114-flat-spot/page__p__2237238#entry2237238