KoF96 AES graphical glitch

Seeing the glitch thread made me remember something odd that happened when KoF96 first came out.

Basically my mate had both Jap & US AES systems, unmodified and both running through RGB. He got a KoF 96 US and it seemed to work fine, except for problems on 2 stages.

On the Yagami team stage and the Boss team stage, there were horizontal black lines, about the width of one block on the energy bar that appeared whenever a character jumped up. He exchanged the cart 3 times, yet get the glitch on every cart. Finally he got one that didn't glitch.

Has anyone else had this problem before?

You know, that may be RGB signal degradation, before I RGB modded my system I had these awful vertical lines visible when playing, however, it was clearly more prominent on some games that other... and in paticular when horizontally scrolling, like a forward/back jump in FF3... I guess the composition of the background elements can exasperate the problem.
That's my thoughts.

*edit* oh, you said you saw horizontal lines... nevermind then.