'BACK PAY

Randy Quaid wants a piece of the back end. The actor has filed a lawsuit against Focus Features, claiming that Brokeback Mountain producers misrepresented the pic as a low-budget "art film" in order to secure his services at a cut rate. Court papers contend that the film in actuality had "traditional studio marketing and distribution" and are thus seeking an award for Quaid (who played boss man to Ennis and Jack) in the amount of $10 million. Focus Features has no comment on the pending litigation.