In every scene Maya creates a set of default objects, some of these are the persp, top, front and side cameras. The options under the "View" menu act on the current camera being used by that particular viewport, so the "Predefined Bookmarks" doesn't actually switch between camera objects.

The options under the "Panel" menu allow you to change cameras and viewport(panel) layout. Hope this helps clear things up!

Edit lol didn't get to post this before your last reply. Does the grid and manipulator handles show in other views? Is "Grid" checked under the "Display" menu?