Viewing external link & clicking browser's back button requires you to login again

For example, from My.SolidWorks, view the "Running at SolidWorks World 2013" post. Click on the link in this post (which brings you to an external site). Click the browser's back button. You're brought back to the My.SolidWorks login page. You should be brought back to the post. Or, the external link should always open in a new tab.

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