Flex -NavigateToUrl("some url", customname) is opening two tabs in IE11 instead of one tab(in same window)

Question

In flex-3, when I click on a link, a url is called using navigateToURL("someurl",somecustomfixedname). IE 8,9 and chrome opens that url once in a tab/window(depends on tab settings), if you click the link two or more times same window/tab will reloaded, which is expected. But in IE 11, on first click a tab/window is opened, second click another tab/window is opened and from third click on wards the second tab/window gets reloaded. I have tried changing the tabs settings in IE11 same as of IE8, it didn't help. Please suggest some solution. This following link has similar to my question(but in javascript)"Why doesn't window.open(url, name) open in the SAME window with IE11?". but no solution provided. I am stuck with this issue, if any one faced this problem kindly suggest a solution.