Viacom is suing Rockband developer Harmonix for $131m, claiming a miscalculation was made during its 2006 acquisition of the studio.

As detailed by The Hollywood Reporter, Viacom's beef lies with earn-out payments made during its purchase of the studio. Earn-outs are paid to the original owners of the purchased company, encouraging people to stick around after the deal goes down.

The thing is, earn-out payments are based upon the future success of the merged company. Harmonix was bought by Viacom at a time when rhythm games were all the rage - and we all know what's happened to the genre in recent years.

At the end of 2010 Viacom sold Harmonix for $50 - less than the retail price of one of its own plastic guitars.

Harmonix is already suing Viacom for $13m over alleged unfair business practices.

It's a sad state of affairs, really. Rock Band 3 was a great game, scoring a 9 in our review, but it didn't sell. Although Pearson says that his sister bought a copy, which is nice.

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