I have a 500GB hard drive in my MBP. Recently it has become pretty sluggish, and I have had problems with iMovie crashing. Figured I need to clean up some hard drive space. When I right click on the HD it states "Capacity 499.25GB, Available 90.14GB" I couldnt believe I had used that much space, so I did some searching. When I go into my user profile and add all my pics, docs, movies, aperture, iTunes, etc. together I get right around 161.48GB. 499.25GB - 161.48GB = 337.77GB remaining. Why is my mac telling me I only have 90GB left??!!