Commented Unassigned: AsyncFileUpload with Firefox 22.0b1 script busy [27429]

I always test my sites with beta versions of firefox, this week Firefox 22.0b1 was released and the AsyncFileUpload started to generate a "script busy" message and it is not working anymore:


> Script: http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/CombineScriptsHandler.ashx?_TSM_HiddenField_=ctl00_SampleContent_ScriptManager1_HiddenField&_TSM_CombinedScripts_=%3b%3bAjaxControlToolkit%2c+Version%3d4.1.7.123%2c+Culture%3dneutral%2c+PublicKeyToken%3d28f01b0e84b6d53e%3aen%3a608fa982-dded-4326-bfe7-b13cdd701e9a%3ade1feab2%3af9cec9bc%3ae4bd8421%3af2c8e708%3a720a52bf%3a4a2c8239:12

Actually you can go the AjaxControlToolkit example to see the error (of course, if you have installed Firefox 22.0b1)
http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/AsyncFileUpload/AsyncFileUpload.aspx

I removed the width and set the type to Traditional according to some solutions, but it did not work... and I installed the last version of the toolkit (April 2013).

With previous Firefox versions, the control works fine.

Any help is appreciated.
Thanks
Comments: I do not understand why this issue is not getting fixed! This does not seem very hard to fix... But perhaps I'm missing something.