Pinvisible

So here's a thing. Today I took a break from the novelty of watching Homestar Runner on the big screen via the Wii browser, and played a little of the original NES Pinball on the Virtual Console.

Apparently when your score clicks over to 100,000 the flippers become invisible. Does anyone know if this is a deliberate feature of the game or just an emulation problem?

ANSWER: No, this is a feature of the original game, apparently. If I'd managed to hold out till 150,000 they would have reappeared and stayed visible until I ran out of balls. Strange stuff.