In IE8, how do I get my closed tabs to stay closed instead of often reopening automatically?

It doesn't happen every time, but often when I try to close a tab by hitting the X on the tab, IE8 closes it and immediately reopens in another tab (sometime multiple tabs it). It's a pain to have to re-close my tab(s) when it should have just closed and stayed closed the first time. How can I get my closed tab to stay closed the first time I close it?|||Get Firefox, problem solved!