Alright, I've discussed some of this stuff on Volvospeed also to no avail, so some of you may have already seen this.
Anyways, I believe that I have a boost leak that will seal under vacuum (which in park on a warm engine has 20in of vacuum) yet produces a large enough hole to vent off all manifold pressure above 6.5psi (the highest boost I've ever seen, even when its 55degrees out). I've always suspected this leak since I got the car (about a year and three months ago) and now that I finally have a real boost gauge I can tell. Anyways, how would you test for that type of leak. Charles (Volvospeed admin) told me to pressurize the vacuum lines with the car off and listen for the leak. Well I couldn't find a hand pump, but I did hook a compressor up to it that had a pressure regulator that I set to 1bar and plugged it in to a free vacuum tree connection, to listen for leaks. I could here some air movin' around but that's about it. (it is just the sound of rushing air through all the tubes, not a leak type sound) The system didn't seem to hold any air whatsoever, my mechanical (VDO) boost gauge showed nothing and just sat there, even with the compressor hooked up, and running. If you don't have any other suggestions, would the dealer or other mechanic be able to easily enough diagnose the problem (is there some type of diagnostic equipment they have?) and how long would it take them to find it? (I'm about ready to take it to the dealer, and want to know what to expect price wise) So if anyone has any ideas, that would be greatly appreciated.

Thanks for all your help.

Oh, and there are no error codes present whatsoever on any of the A sockets