Other mistake: The credits for the movie say that they are in alphabetical order, but Peter Cullen is listed before Scatman Crothers.
Other mistake: When Perceptor pops up to tell Blaster to radio Prime, Blaster acknowledges that Perceptor is there before he even sees him. And I doubt he could of heard Perceptor because of the amount of noise the lasers were making, and Perceptor didn't make any noise. (00:14:45)
Other mistake: When Devastator throws a piece of the wall during the attack on Autobot city, his face is completely blacked out. Looks like they erased it and forgot to draw it back in.
Answer: The planet was called Lithone. According to a comic book adaptation, the race that dwelled there were an offshoot of the Transformers who were more emotional. The limited information given on the only two characters named in the movie, Arblus and Kranix, shows that they can transform even though this is never shown.