Hi. My sister just bought a previously owned Mac iBook G4 with OS X 10.4. I own a PC myself, so i'm pretty much hopeless with trying to troubleshoot on a Macintosh. The problem I am having is that every time that I try and download a program from safari, it downloads but when you click on the icon on the desktop or in the new folder, nothing happens except that the program icon appears briefly in the dock and then dissappears right away with seemingly no result. Like I said, it was previously owned so there may be something wrong here, but if this is a simpler problem, I would really appreciate some help in dealing with this problem. Thanks.