Variety reports that out producers Craig Zadan and Neil Meron (Chicago, It's All Relative) have walked off an ABC movie about singer Lena Horne after she vetoed Janet Jackson as the film's star. Jackson was all set to play the famous vocalist until Horne refused to sign her contract unless Jackson was removed from the project. Horne and her daughter, Gail Lumet Buckley, were said to be incensed over Jackson's infamous flash at the Super Bowl. Zadan and Meron walked out in solidarity with Jackson, and ABC insiders now feel that, barring the casting of another superstar, the film may never get made. Spokespeople for Zadan and Meron said the producers are looking for another project for Jackson.