AI tailfins missing

I have noticed this problem several times, and at different airports. On rare occasions, I see an AI plane without a visible tailfin! I remember seeing an Iberia A320 taxiing out to the runway at Heathrow without a tailfin (presumably the pilot forgot to complete the external check before entering the cockpit), and I have just seen a TNT 737 landing at Dublin minus a tailfin (a magnificent demonstration of flying skill that should be rewarded with a knighthood).

Has anyone else seen this, and is there a solution?

I use a mixture of UT2 and freeware AI plane models.