Drop down menus and Firefox1.5 / Mozilla 1.7.12

Using Firefox 1.5 browser when selecting an item that has a drop down menu I am having to click the down arrow then move off the selection click some were and return to the down arrow before I get the droupdown menu. I am seeing this action in webmin, usermin, and virtualmin. When I use Konqueror the KDE browser I just select the downarrow and the menu is present. This looks to be a problem only with Firefox and Mozilla 1.7.12. This is not a show stopper by any means but I thought you need to know.