identical target=“_blank” behaving differently for different hrefs

[_dEViANt_]

In IE, LinkedIn opens in a new tab, SO opens in a new window. Why is that when both are identically structured (\[code\]target="_blank"\[/code\])?HTML:\[code\]<ul class="xlink"> <li><a href="http://www.linkedin.com/profile/view?id=123" target="_blank" class="xlinkedin"></a></li> <li><a href="http://stackoverflow.com/users/123/abc" target="_blank" class="xstackoverflow"></a></li></ul>\[/code\]CSS:\[code\].xlink { float:right; margin-top:18px;}.xlink li { float:left; display:inline; margin:0; padding:0; margin-right:2px;}.xstackoverflow { float:left; width:30px; height:30px; background:#222 url('../images/stackoverflow.png') no-repeat 4px 3px;}.xlinkedin { float:left; width:30px; height:30px; background:#222 url('../images/linkedin.png') no-repeat 4px 3px;}\[/code\]