When using javascript to swap images the HTML is updated fine but what Opera actually displays is not unless you scroll or resize the window. A picture of what happens when you scroll explains it best.
Any ideas?
EDIT: The source of the problem seems to be that the image is inside a div that has float right.
EDIT2: This http://trac.dojotoolkit.org/ticket/3158 would suggest that it's a bug that was fixed and is back again.