From TMZ:

Vanessa Hudgens claims she's been double crossed -- and now she's suing her former manager for allegedly breaking the terms of a very secret and very expensive settlement deal.
The High School Musical star just filed a lawsuit in L.A. County Superior Court accusing Johnny Viera of violating a court-approved settlement. Vanessa says Johnny broke his promise by making it look like he still represented her on his MySpace page.
Vanessa forked over money to settle Johnny's beef with her back in April -- he had sued her for allegedly stiffing him on commissions.
Vanessa now claims since Viera broke their secret settlement -- she should get her money back. We'll see if the judge agrees.