Lou/Mark - Which air file are you guys using?  I just switched back to the original and it seemed to fix this problem.

I guess a better way to ask this question is with version 2.4, which mods are you installing ?

I think I have the following:
INS addition
Sound Fix
DME Gauge Switching
Pressurization Fix
V-One guage
Flight Model by Michael2 - This includes the changes to aircraft.cfg and the EPR cab files, TAT and MAC, plus the air file.