Hey Bombs!
Photobucket killed all my images here at SAS, so I'm reloading this one to VGY.me - to try it out.
Image is my version of RAF Manston for Canon's BETA Channel Map, to launch and recover twelve (maximum) fighter-sized aircraft (from one end of the runway or the other). In all the testing I've done, this is the only completely reliable layout of runway, taxi and parking waypoints.
Without knowing all the coding going on in the background, it appears to me that the AI can go FUBAR whenever it has a "choice" of which waypoint to follow on the ground (or even in the landing pattern!), whether it's multiple runways or even just taxi route "intersections".
I've always found this layout - a single double ended runway with a single taxi route at each end - to be by far the most reliable (usually 100% success for AI landing, taxi-ing and parking). For me it makes it much nicer to plan missions when you can count on where the AI will park at the end - they will always fill the parking spots in order with this layout:
The other thing I've found that will "kill" a parking spot is another object too close - so that's something to look out for. Once all the "effective" parking spots are filled, the AI will despawn halfway to the first runway waypoint (in my experience).
Hope it helps.
KB