On IE 7, jQuery's fadeIn() and fadeOut() requires the user to move the mouse around the area to see the update, why?

Question

I have some jQuery's fadeIn() and fadeOut() and it works well in IE 7 and IE 8 (with the IE 7 Compatibility Mode) -- It works perfectly on Firefox, Chrome, and Safari as well.

However, some part of it will not show any update of elements fading out and new elements fading in, until I move the mouse around that area -- then the whole region will all of a sudden "update" itself to show the new content.

Anybody had that experience before and know how to fix it?