Created Unassigned: The Tab-Control doesn't run in IE8 since december release [27652]

The problem occurs since the december release of the ajaxcontroltoolkit. When i use the september releas, everything is fine.

Error: Object doesn't support this property or method

Details zum Fehler auf der Webseite (sorry it's a german IE)

Benutzer-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; WOW64; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; InfoPath.3; .NET4.0C; .NET4.0E)
Zeitstempel: Tue, 11 Feb 2014 10:31:51 UTC

Meldung: Das Objekt unterstützt diese Eigenschaft oder Methode nicht.
Zeile: 22
Zeichen: 939784
Code: 0
URI: http://abcdefg.xyz/AJAX/CombineScriptsHandler.axd?_TSM_CombinedScripts_=True&v=0IoZoGZ8agvJe776Qg8bdPtBElWve_UJXBxrWZ4MoR41&_TSM_Bundles_=&cdn=False