Greybox is nice to use having the modal window and all. I have found one problem so far when using IE8. It works good except when closing the Greybox. In IE8 (Browser Mode: IE8; Document Mode: IE8 Standards), the greybox does not close properly. It shrinks to a 100x100 square and positions itself in the upper left corner (0,0) of the browser window.

I have found by adding this meta tag directly on the page it now closes, though a little rough. Meaning, you still see the square get positioned, but it then closes fully a split second later.

<meta http-equiv="X-UA-Compatible" content="IE=7" />