markers are not showing on google map after refreshing the page in IE

I have hundreds of markers on the google map. The markers are only shown when the page is loaded the first time. when I refresh the page in IE, the markers 开发者_Python百科are gone. I'm using markermanager to store the markers. I'm sure the markers do exist on the map as I tested using some methods from the markermanager. The only way that I can make the markers show again is to clear the cache or enable "always refresh from server" from the IE developer tools. I've also tested the page in other browsers, they all work just fine. Only IE has the issue. Any ideas on how to fix it?