Eclipse 3.3:
private boolean menuExist()

{ return menu != null && !menu.isDisposed(); }

We had to add it in subcloass for our logic.

Eclipse 3.3:
protected boolean menuExist() { return menu != null && !menu.isDisposed(); }

Used in a couple of MenuProvider's.
private boolean menuExist()

{ return getMenu() != null && !getMenu().isDisposed(); }

Solution:
remove our implementation.