Commented Issue: Tab Container throwing error Can't move focus to the control because it is invisible [27218]

On my web page I have 1 tab container with 4 tabs. On tab 4 is another tab container. When I start the site I get an error
Can't move focus to the control because it is invisible, not enabled, or of a type that does not accept the focus.
It is coming from
_setFocus: function (obj) {
$get("__tab_" + obj.get_element().id).focus();
},
which is dyamically generated (as best I can tell). I downloaded the 4.1.60623.0 version of the toolkit. Copied the AjaxControlToolkit.dll to the bin directory of my site. But I'm still getting the error. I'm not sure how to upgrade the controls on the page. Please help.
Thanks
Comments: I changed the ScriptManager on the Master page to the ToolkitScriptManager1 and now I am getting the "Can't move focus to the control because it is invisible, not enabled, or of a type that does not accept the focus" error on _setFocus:function(a){$get("__tab_"+a.get_element().id).focus()} which again is some dynamically generated code which is still referring to the nested Tab container.