I removed the plugin which was installed by acrobat automatically. I first turned off safari, then simply removed the 2 acrobat plugins. After that, I restarted system and found pdf was opened by preview in safari now, but the mouse cursor became very jerky while I was viewing pdf. It would turn back to normal once I switched to web. I think it must have something to do with acrobat plugins. Because viewing pdf in safari is perfectly normal in my guest account, which was not modified by acrobat plugins. I prefer using preview to view pdf in safari. Can somebody plz give me some advice on solving cursor problem? THank you!