I'm doing a virus scan with avast! for mac os. (yes I know that everyone says there is no need for virus protection but I have a ton of pictures on my computer and backup drive and hope to start a business with them some day. Don't want it all to get messed up by some possible virus yet to be created. Plus its just nice to do for our windows using friends!) Anyways, it's not showing any viruses but it is showing several warnings. When I click on them to see what they are the message reads- "There is no special description for the error 13 available. The operating system description (English, not localised) says: Operation could not be completed. Permission denied" Does this mean I have some corrupted files to take care of and if so, how do I do this? Just out of curiosity, does anyone else use virus protection (if yes which one works the best?) Thanks for your help guys!