All good points, I'll need to investigate some of that a little closer.
A little explenation to your comments;
I'm using sequential injection, and they are syncronized by a cam sensor. It is working fine, I know this because I was thinking the same thing as you, nicd.
Belive it or not, but I have the same issue even if the cam sync sensor is disconnected. -Wait, maybe this is what the "bug" is!? (In the ECU?) Maybe it appears to sync up, but the reality is different?
A vakuum leak is tricky sometimes, but I can't see anything wrong on the MAP though. I imagine I could see something there. Besides, there is really only one place a PMO ITB can leak; the brake booster connection from runner no. 2. (Or to the MAP sensor, but it seems to be solid)
So I am going to check out the possible leak anyway, along with the power supply to the injectors, checking the resistance in the wires all the way from the ECU.