Hello mate i read your post about diagnostics. I could reccomend you garage in witney, they are volvo specialists i always service my car over there and they never charged me for computer diagnostics. They are far mor cheaper than main stealers and offering highest standard of service. Call Derek he is the owner and tell him what is the problem, i am sure that he will be able to help - very nice guy. You can tell that you heard about him from a me ( lucas blue v70r from oxford) member of voc.
You can go on their website to find contact.
http://www.da-autos.co.uk/
Regards, luk