Could anyone please help me solve this problem I'm having with my Mac? All the documents, files and icons displayed on my desktop keep disappearing and then reappearing whenever I do anything - though especially when I save or update something, create a new folder or rename a document/file. Sometimes they don't reappear at all and I am forced to restart the system. I use a Mac Mini Power PC G4 (1.2) with OS X 10.4.11 and I have an external hard drive which I use to save most of my files and documents onto. Any advice on how to fix this would be greatly appreciated. Thanks.