The CSS class assigned to disabled tabs in the 15.1 Toolkit differs from previous releases. The "__tab_disabled" class was assigned to the tab previously (a SPAN) and now in v15.1 it gets assigned to the hyperlink. The "__tab_active" class works as it did previously getting assigned to the tab (SPAN). This would seem to me anyhow to be inconsistent behavior.
Version 7.1213 HTML:
![Image](https://staff.washington.edu/lwrogers/outgoing/AjaxControlToolkit/TabContainerDisabledBug/tabContainerOld.png)
![Image](https://staff.washington.edu/lwrogers/outgoing/AjaxControlToolkit/TabContainerDisabledBug/tabContainerOldHyperlink.png)
Version 15.1 HTML:
![Image](https://staff.washington.edu/lwrogers/outgoing/AjaxControlToolkit/TabContainerDisabledBug/tabContainerNew.png)
![Image](https://staff.washington.edu/lwrogers/outgoing/AjaxControlToolkit/TabContainerDisabledBug/tabContainerNewHyperlink.png)
Comments: Related changeset [58474a6953d9](http://ajaxcontroltoolkit.codeplex.com/SourceControl/changeset/58474a6953d9cebac5958e8ccfbd0990a758aa1a)
Version 7.1213 HTML:
![Image](https://staff.washington.edu/lwrogers/outgoing/AjaxControlToolkit/TabContainerDisabledBug/tabContainerOld.png)
![Image](https://staff.washington.edu/lwrogers/outgoing/AjaxControlToolkit/TabContainerDisabledBug/tabContainerOldHyperlink.png)
Version 15.1 HTML:
![Image](https://staff.washington.edu/lwrogers/outgoing/AjaxControlToolkit/TabContainerDisabledBug/tabContainerNew.png)
![Image](https://staff.washington.edu/lwrogers/outgoing/AjaxControlToolkit/TabContainerDisabledBug/tabContainerNewHyperlink.png)
Comments: Related changeset [58474a6953d9](http://ajaxcontroltoolkit.codeplex.com/SourceControl/changeset/58474a6953d9cebac5958e8ccfbd0990a758aa1a)