Hrm. Seeing as how it would be really easy to fix that by throwing better hardware at it, it's probably a software issue. Not a good sign.
The guy writing that, IIRC, was a member here until the "Foley is t3h debil" crowd ran him off. I regret that having happened as the guy (the dev, not Foley) seemed to have his head on straight and was just trying to make a living in the arcade industry. He would be able to answer this question for us.
These days in the pinball industry, with home sales an ever increasing segment, this could actually be an issue at their retail price.