hi m8 ive got the same problem as you ive had this for the past year on my 03 tdi galaxy in this year ive changed the belt+ tensioner+ p/s pump + p/s pulley +steering rack been to umpteen garages as they all said one thing too another to another now they are saying try a smaller belt tryed that and its the same as was last year .. i took my daughter to look at one on saturday so i mensoned it to him and he said straight away change the alternator pulley and that will solve the problem and not to try changeing anything else too late for he as cost me hundreds i hope this helps you and saves you a lot of cash regards gaz im waiting now for a pulley
