Steps to Reproduce:

1. Create a form and use the headers tabs extension to create at least 2 tabs.
2. A multiple instance form should be added to some tab (lets call this tab the tab 1, and the other tab the tab 2).
3. Edit the page with the form and add enough entries in tab 1 so that the multiple instances are minimized.
4. Save the page.
5. Assuming we are on tab 1, if the page is reloaded, the minimization of the form instances works fine. If we switch to tab 2, reload the page, and then we switch to tab 1, the form instances are not minimized.