BaD CrC, Thanks for the come back on the question. That's what I was afraid of (Lack of compatibility between different versions of missions created with different Mission Editors in BS). Some of the more complex missions I created started working when I removed and reinserted the enemy helos, if that helps anyone out there. Guess I will start from scratch as you recommended for the rest, unless someone knows further info or has a silver bullet. Bother, less time spent flying.