Each time, I closed MSIE, I got a small black window, which disappeared so quickly, I couldn't even read its title, but I could read pieces of it anyway after trying several times and it was "SiteAdvisor for IE". I installed SiteAdvisor with the install-file "sasetup.exe" monitored by "Total Uninstall", like any other software and that was the reason. I uninstalled/re-installed SiteAdvisor without using "Total Uninstall" and the small black window wasn't there anymore. Weird very weird !!! Nothing is perfect. My advice : don't install "SiteAdvisor for IE" monitored by "Total Uninstall".