Steps to reproduce:

(before #2255, revert that PR for repro or use code in post below)

1. open https://dev.agiletoolkit.org/demos/interactive/tabs.php
2. click "Modal popup" tab
3. click "Load Lorem" button
4. click on the dimmer background to close the modal
5. click "Static Tab" tab
6. click "Modal popup" tab again
7. click "Load Lorem" button
8. click on the dimmer background to close the modal
9. repeat step 7 - and notice, the modal is empty! (the modal load AJAX is not even sent)