Youtube draggable element problem

Hi,

I'm having a strange problem when i want to specifically drag a youtube element in every theme: spirit, fixer, panino & scribe. There is only a dotted border shown and the whole upfront theme "freezes" like i have to press an ok button, which isn't visible. I hoped it was magically fixed with the 0.4 upfront update, but the problem is still there on all blogs of my wpmu install.

Note: There is no additional ajax/js/jquery script installed on the theme and there is also no additional css.