I expect the user has a Microsoft Mouse, probably an Intellimouse, and the issue here is likely to be the bad microswitches they used on earlier models which resulted in a second click being registered on releasing the button. There are two fixes, one is to replace the mouse with another one, or download MouseFix from this site (scroll down to find a description of problem) http://www.danieljackson.co.uk/fun/old/ You need to extract the MouseFix.exe and MouseFixDll.dll somewhere (I used to put it at C:\MouseFix). Run MouseFix.exe and then try your back button again. It will not go back twice. To use permanently create a shortcut to the MouseFix.exe and place it in the Startup folder in the Start Menu. The author originally created it for his failing Microsoft Intellimouse with the problem similar to the microsoft KB article http://support.microsoft.com/default.aspx?...kb;EN-US;266738