So I finally got my brother to buy a Macbook Pro for college, and I've been helping him download some good programs (Perian, HandBrake, Firefox, Schoolhouse, etc.), BUT heres the problem: We download a .dmg file. It appears in the desktop and the download box. If I select the file with a single mouse click to mount the disk, the .dmg file immediately disappears. I can't find it in the finder, nor is it in the applications folder. I have to right-click the item in the download window and select "Reveal in Finder." When I do this, it pops back onto the desktop and back into the finder window. When it does this, it is no longer a .mg file, but a application file with a pretty icon. I can then drag the application into the applications folder and it installs and everything works normally. Please help! Thanks in advance!