2.8.3 issue: Closing the image window for TinyMCE editors

I just tested the new 2.8.3 fix, trying to insert an image using the method that was broken for Tiny MCE editors. When I try to click “Close”, nothing happens. I have to select something and then cancel the dialogue box.

Any thoughts?

Any chance it’s a CSS layering issue that’s causing the close button to be unclickable? Assuming it’s one of those X type icons (haven’t looked at this particular dialogue box) sometimes the heading of the box will overlap the close icon and render it useless.