Could anyone picture High School Musical without stars Zac Efron, Vanessa Hudgens or Ashley Tisdale? If the cast doesn’t come to an agreement with the studio soon, that could be the case. With the record-breaking success of HSM2, Disney execs are rushing to sign the stars for a third film, but conflicts over salaries and script approval are holding things up -- and with good reason! The first HSM grossed $100 million. Zac’s been offered $2.75 million, says an insider, and other leads have been offered $1 million. But no one has signed up yet. “Zac’s telling the other actors to make sure they get what they deserve,” says the insider.Could the battle put the next movie in jeopardy? Will Zac bail out and take on another role – and will the others follow his lead? Check out the new issue of Life & Style, on newsstands now, for the latest details!" information credit: from Miley Cyrus