Memory Access Violation

OK guys, I think this is a BUG. Check this out and tell me what you think.
I've added some extra checks to narrow down the problem. Here's the code:

	For thisBullet.bullettype = Each bullettype
		exitloop = False
		For thisship.shiptype = Each shiptype
			If thisship\ID = 2
				If thisbullet\image = 0 Then DebugLog "thisbullet\image=0"
				If thisship\image = 0 Then DebugLog "thisship\image=0"
				If thisbullet=Null Then DebugLog "thisbullet=null"
				If thisship=Null Then DebugLog "thisship=null"
				If ImagesCollide(thisbullet\image, thisbullet\bulletx, thisbullet\bullety, 0, ship\image, ship\shipx, ship\shipy, 0)
				EndIf
				If ImagesCollide(ship\image, ship\shipx, ship\shipy, 0, thisship\image, thisship\shipx+400, thisship\shipy+300, 0)
				EndIf
				If ImagesCollide(thisbullet\image, thisbullet\bulletx, thisbullet\bullety, 0, thisship\image, thisship\shipx+400, thisship\shipy+300, 0)
					FreeImage thisBullet\image
					Delete thisBullet
					FreeImage thisship\image
					Delete thisship
					exitloop = True
				EndIf
			EndIf
			If exitloop = True Then Exit
		Next
	Next

Now so far in my tests, I've had the MAV occur on the FIRST ImagesCollide line (which isn't so surprising) but I've ALSO had the MAV occur on the THIRD ImagesCollide line. And you'll notice that the THIRD line uses the same images and objects that the first two do, so it SHOULD HAVE MAV'd on one of the first two if it was MY mistake, don't you agree?

Also, in case it helps, which I doubt, but here's some of the object data for the objects in question one of the times I got the MAV on the THIRD ImagesCollide line:

thisship.shiptype
 id=2
 image=25195528
 shipx#=-440.574
 shipy#=-910.735
 rotation=169
 velocity#=-1.0

thisbullet.bullettype
 image=25200528
 bulletx#=-84.7722
 bullety#=-635.957
 xangle#=0.848048
 yangle#=-0.529919
 velocity#=10.0