When I said "original" I meant my original boxed Gold Edition install with SP1, SP2, and Acceleration so I'm OK there.But since you say 'original FSX on XP': note that AiCarriers requires at least FSX-SP2.
Rob

Today I'm moving AICarriers.NET from Program Files to by itself on my C:\ drive and we'll see if I can get it working from there.
I may also try your arrangement of dual installation with both Java and NET versions.