I recently purchased Norton AntiVirus 11 for my Mac, which runs on OS 10.5.8 and it won't run. I can get the program to start, but when I click the 'Perform Virus Scan' button, it turns blue for about 4 seconds and then goes back to no color. I have tried uninstalling and reinstalling, but that changes nothing. When I turn off my computer at night and start it up the next day and try to open the NAV, it tells me that it can't open due to the prefernce file not being there. I contacted the chat help and they suggested running the disc utility permissions repair, which produced some permission errors. The Norton tech then suggested to contact Apple support, which I did the next day. I was told by them that the permissions errors should not be causing this problem and there was a conflict issue. I googled some of the errors and found an apple support url titled 'Repairs you can Safely Ignore' http://support.apple.com/kb/TS1448, which covers all of the permission errors that I came across. Tonight I went back to Norton's chat help and got nowhere with the tech, who just kept repeating that it wasn't a Norton problem and didn't want to discuss it further. I don't know what to do. I appreciate any help and thank you in advance for whatever assistance you can provide.