Everytime I wanna open a programm or movie that I've just downloaded, it won't work. Though there is no problem in playing downloaded mp3s and copying them to itunes, it's somehow not possible to open/start downloaded programm-files (any type of them!) and movie-files. I also can't drag them to my desktop or somewhere else. When I click on them or try to move them just nothing happens!
I run an OS X 10.3.9.