Only work if mouse enters from outside the element ¿O_o? (read for details)

I have the extension configured to only show the popup if the Crtl key is down. If I already have the mouse over an thumbnail and press crtl key to show the popup, nothing happens, even moving the mouse over the thumbnail, I need to move the mouse outside the thumbnail and hovering again. A minor nuisance, but it will help to improve the extension ñ_ñ.