Sorry chaps for not getting back sooner. Updated email address and got no notifications.
Anyways, it was May this year when I did that adjustment on my turbo and the car has been impeccable ever since! No juddering at low rpm.
To answer some of the queries, even if the screw shows a little height,which mine did, give it a full turn or 2 upwards.
If the turbo has been off dont forget to plug the actuator/pierburg pipe back in otherwise you wont get power early on.
It's a doddle to get the turbo off and if you need to replace it you only need the internal part of the turbo not the housing. There was a guy on eBay selling these for around 200 quid. He was from poland and they were british made. I will try find the link and post up.
shop name PROAUTO EU.
Alternatively you can try cleaning the waste gate area. Not sure what with but I was reading that this is a known issue experienced by some VW Passat owners also.