Continuing on from my other thread which was getting too long.........

After driving home from TOTD with no probs went out again last night and the car wont hold any sort of boost above about 9psi now, the needle just flaps around and the car jerks about just like the actuator is giving up or there is a split hose.
So today i've tried another actuator, taken all boost hoses off to check for leaks, removed my dump valve in case that was leaking, checked manifold for cracks and found nothing!!

What else should i be checking?