magic mouse have to keep clicking and clicking

so every time I visit a site with a drop down menu I click with the mouse and the menu pops down then up again quickly. It's like a carnival game I just cant win. after about 10-20 clicks the menu will stay dropped so I can make my selection. I've never had this problem before with other mouses. it's very frustrating and only works when I hold the button down. I just want to be able to click and have the various website menus stay down.