Javascript error with image preview

Hi i m testing the 2.9 of socialads, it looks like i have a problem when i try to upload a media (image) .

The javascript error come from mootools-more:

In FF:
Erreur : TypeError: k.indexOf is not a function

In GG:
Uncaught TypeError: Object #<HTMLIFrameElement> has no method 'indexOf'
g
addEvent
ajaxUpload
onchange

Joomla 2.5.9
MooTools.More=version:"1.4.0.1",build:"