All the reasons why this was not working is because the div I need to show, when the mouse moves over an item in the toolbar, has to be shown on the parent frame. This is required as the toolbar is only 22 pixels in height. As I have one div in the toolbar trying to communicate with another div in the parent frame, as is, it will not work. I made a test by increasing the height of the toolbar and using the same layer for everything and that worked immediately. So, I will see if there is some kind of ways to achieve the same from the parent code, so the toolbar div will be able to detect that the mouseout event is in fact hovering over a div from the parent.