Having trouble with playing videos on youtube and other sites with flash content. I upgraded to Mac OS X 10.7 Lion and Safari 5.1. I've uninstalled and reinstalled the latest flash player several times, and messed with the safari>preferences>security>enable plug-ins If I have the enable plug-ins box deselected and go to youtube, videos don't load and it says I have to upgrade my Adobe Flash Player (although it is up to date) If I have the enable plug-ins box selected and go to youtube, videos don't load and it says Plug-in Failure. I've verified and fixed my disk permissions with Disk Utilities. I've turned off Safari Extensions even though I didn't have any installed. This is my work computer, where I'm set up as a user and don't have access to the admin login because my IT guy is out on vacation. So at this point since it seems like I've tried everything else that people have suggested, I'm assuming that it has something to do with having to install the flash player while logged in as the admin. Would this make a difference? I have a iMac at home with Lion and Safari 5.1 and have no problems at all with it. I've set up my work computer with the same settings as my home computer but yet I still get problems playing flash content. Help please... Another thing I noticed that is weird... If I go to twitter.com, the home page will flash a couple times like its trying to reload or something, then safari will crash with a message saying, " Safari can't display this webpage, safari has repeatedly encountered an error while trying to display http://twitter.com/" Also I have the Spotify app. After I log in it will immediately crash. I'm not sure if these are related to my flash problem but I don't experience either of these problems on my home computer which seems to run flash completely fine. One last thing...I Deleted Flash cookies with the Flush.app, and no help.