Well how about this? I've been through it all! 2 seperate (different firms) regas and degas,then finally got it sorted at a firm I used a few yrs back, the invoice reads, I quote,"check air conditioning system,vacuum down and check for leaks,regas as necessary,inlet valve found to be defective,order replacement pipe assembly,fit to vehicle and re-gas finally check for correct operation". The Inv total is £264.38.This had to be done in 2 seperate visits, the 1st visit they did attempt to replace the valve but finally had to order a replacement pipe assembly from the main VX dealers, this took 3 weeks to come from Germany, and although I can't recall the exact cost it was well into 3 figures.All in all Andy, it also has made me wonder about the valves, could it be some incompatability issue between them and the regas machines? The manager did make a point to me that it is crucial that the systems must be purged of all contamination and moisture,and obviously the valves will play a vital role in this.Anyhow the air con is now OK,and has worked very well it is important for my wifes health.