When using async: false for ajaxOptions, all tab interactions break after selecting the dynamically loaded tab in IE7.

To reproduce

1. Use IE7 (and below?)
2. Interact with existing tabs, notice they behave as expected
3. Click on "Load new tab" button
4. Interact with original tabs, notice they still behave as expected
5. Click on the dynamically loaded tab
6. Interact with any tabs, notice the JavaScript error and tabs no longer work
Toggle async setting to true in the source and retest, notice tabs behave as expected