Mouse over pop up layer

Hi all

I have created a small image to mouseover so that it popups a layer with the larger image plus dark tranparency behined it, and all works fine but you cannot get rid of the pop up layer unless you move the mouse pointer off the page completely either left or right..just moving if off the 100X 100 pixel image is not enough even for me to get to the original mouse down layer is a pain in preview let alone clients!.. Is this normal mouse over popuplayer behaviour (which i doubt) - ANY IDEAS WHAT I COULD HAVE DONE WRONG?

scruffy

Dog

I believe the problem is the dark transparent area.
This is part of the popup.

Cheers aridzone:)

Thought as much as i like the darker back ground tranparency like the picture pop up gone back to my usual lock pop up layer no problems there;)