Menu not functioning well

i am facing the problem as the menu is not functioning well. After i choose the pages that drop down from the menu, i have unable to choose any other from the drop down list, as it is not display anymore. I have to refresh the whole website only able to view it again. Please advise me on this. My website URL : www.weddingplanningmalaysia.com

please advise . thank you

Hi!
What is the browser you are using? Actually I tried to go to a page by link in drop down menu and drop down menu continued work. In other words I didn't sean bug.