Inconsistent layout sizing on different QStackedWidget pages.

I have a dialog box that contains a QStackedWidget with four pages. The desired behaviour is that the dialog assumes the smallest size that will accommodate all pages. Since Qt4.8.0 there is a problem that the size seems to change to the smallest size for some pages and when switching pages changes the dialog box size. What is really confusing is that it does not behave consistently: duplicating the contents of a page that is causing the resizing bug to a new page creates a page without the bug – even though a diff of the XML shows that the pages are almost identical.

Steps to reproduce:
1. Load the attached .ui file in Designer
2. Edit > Preview...
3. Use the stacked widget < > buttons at top right to switch between pages
4. Note that pages 2 and 4 makes the dialog smaller

Additional information:
This cannot be reproduced if using Qt 4.7.4. This is a regression issue caused by the change done in QTBUG-7792.