I had this working in VFP3 but in VFP5 I can't.
I thought that returning .F. in the Page.deactivate would prevent the clicked tab page from activating.
Here's some code

* --- Page1.deactivate ---
RETURN THIS.PARENT.deactivatePage()

* --- Pageframe.deactivatePage ---  (custom method)
RETURN THISFORM.Save()

Now if the user clicks on Page 2's tab and the Save() returns .F. I would expect Page 1 to stay active.
So I've gone wrong somewhere, 'cause it's not working. Any clues?