I would think it would have to do with this:
I can't make these links work. Look up Press Release: IPB sale of assets to Pinball INC dated 5/19/09
https://groups.google.com/forum/m/hl=en&fromgroups#!search/Pinball$20inc$20IPB/rec.games.pinball/m6_-1mwauKk
https://groups.google.com/forum/m/?hl=en&fromgroups#!search/Pinball$20inc$20IPB/rec.games.pinball/m6_-1mwauKk