Closed Unassigned: IE8 TabContainer Not Visible [27625]

Using Net Framework 4.03. Ajax Control Toolkit 4.1.7.1213 (14/12/2013)
The Tab Container Control in IE 8 is not visible (OK in IE10)
The error is "Object doesn't support this property or method"
File: jQuery.Tabs.TabPanel.debug.js
Line: self._tabIndex = opt.owner.get_tabs().length;