heresjohnnyb I realize that there could be some concern as to the set up of the VAV's themselves. It would not hurt to check how the calibration function is performed by itself as Sycontrol has stated. Its certain that that static pressure can be maintained through CPL if set up for this type of control. If that's the case you will need to identify which CPL file is used and verify that it is set up correctly.
Also check the Intellipak which appears to be listed as CCP01-RTU01 which has a flow sensor failure. It is possible that the transducer has failed or maybe its performance has degraded.