This "feature" in Windows 7 has caused me more trouble that you'd think would be possible. With my work laptop, the placement of the mouse buttons under the track pad makes it super easy to hit the middle button when I meant to hit the left button, and boom the tab is gone.
It turns out that the answer is simply to edit the mouse setup properties for the track pad; the definition of each button is fully configurable. I made the middle button the same function as the left button and my problem was solved.
Here are some links. This first link describes the problem perfectly but not the solution so much:
http://www.xyplorer.com/xyfc/viewtopic.php?f=3&t=8148
Here's the (in retrospect, not very related) link that got me to realize that I could just change the mouse button settings through the control panel:
http://www.sevenforums.com/general-discussion/34877-middle-mouse-button.html
