Winklevoss TwinsCameron and Tyler Winklevoss have resumed legal disputes against Facebook concerning their $65 million cash-and-stock settlement with the company, reports CNET.

The original settlement centered on claims that Facebook founder Mark Zuckerberg stole the Winklevoss’s idea for a social network while working for them. The legal dispute was thought to be over after statements by the Winklevoss brothers, in a filing with the 9th U.S. Circuit Court of Appeals, indicated that they would not ask the U.S. Supreme Court to hear their appeal.

However, the Winklevoss brothers filed a motion Friday with the U.S. District Court of Massachusetts asking the court to determine whether Facebook and Zuckerberg “intentionally or inadvertently suppressed evidence,” according to the CNET report.

The dispute by the Winklevoss brothers claims the 2008 settlement was based on an incorrect valuation of Facebook and therefore not accurate. Facebook is reportedly aiming for an IPO in early 2012 and could be worth up to a $100 billion valuation. In January, Goldman Sachs valued Facebook at $50 billion.

It makes sense that the Winklevoss brothers would defer an appeal to the Supreme Court since they are still pursuing legal action in the lower courts.