I think the theatre version is British .. honestly .. here in Canada I'm thinking that might be officially the way, but I'd probably would have spelled it theater (lol .. my spellcheck just underlined the theater version). Obviously the American spelling is much more valuable .. but your version still isn't bad. I'm pretty sure i saw that on closeouts in the last few days .. so the fact I didn't buy it at closeout probably says something .. but I did note it as one of the better ones.
Try to find who has voicetheater.com and sell it to them $$$ maybe? Definitely let me know how it goes!