My S1 overboosts as soon as i hit 14PSI of boost and even my local rollers cant understand it ???

I used to be able to run upto 21PSI (Not Advisable) on my Standard Turbo before any probs...

Now Ive fitted a Chargecooler and Brand New Stage 3 T3 running on incar adjustable boost, i cant boost above 14PSI

Ive contacted the Turbo Supplier who were very helpful and say that overboosting has nothing to do with the actual Turbo and from what i can see all my pipes are ok.

I took it to the local rollers to get set up with the boost peaking @ 17psi dropping to 15psi but he couldnt get it do this boost because of the overboosting and he couldnt understand why ???? any ideas peeps????

All Suggestions Appreciated PeePs Im lost with this One?????

CheeRS Adi