For a while now, I have noticed that sometimes when I delete e-mail messages by clicking on the Delete toobar button, two messages get deleted.  This didn't happen often so I ignored it.  This morning (well, afternoon) I fired up Outlook and tried to delete an obvious spam message (something about increasing size) by clicking on it.  To my surprise, Outlook opened the message!  First, I suspected the message contained a hack that took advantage of some unknown vulnerability to auto-open the message on selection.  I tested clicking on a few other things like the window system menu.  Wow, the window closed on single click!  So its not a hack.

I googled searching for "IntelliMouse Double-Click" without much success.  Searching the newsgroups found the problem.  The problem was caused by a faulty microswitch.  Still, it was strange because IntelliMouse double-click problems were reported in 1999 to 2000, yet I bought my mouse late 2001 at Fry's.  More middlefinger salutes to both Microsoft (for not recalling the faulty mouse) and Fry's (for stocking faulty mouse).