Closed Issue: Javascript error loading hidden TabContainer [27388]

I have a hidden TabContainer on my page. When the page first loads I get a Javascript error when the TabContainer attempts to set focus to its first tabPage. In the interim I have reverted to a previous version of the Toolkit, which works.
Comments: Merged with item [27813](https://ajaxcontroltoolkit.codeplex.com/workitem/27813)