I have had a number of problems with Safari since upgrading to Lion. When moving between web pages using two finger swipe on the track pad, Safari will sometimes stop scrolling up and down. At the time this happens, quitting Safari becomes a problem - the quit option in the menu is greyed out and cannot be selected. I have to "right" click on the safari dock icon to quit, sometimes have to force quit from the main menu. A couple of times it has frozen and I have had to restart. Any ideas?