I recently installed Mac OS X Lion on my Macbook Pro. I plugged in my external hard drive and my computer recognized the HD and even let me access files on it. However, when I tried to copy a movie onto it, it gave me an error: "The operation cant be completed because an unexpected error occurred (error code -8003)." I decided to try a different file, the same thing happened. I tried a USB flash drive and the same thing happened. I checked the permissions for them and it says "you can read and write" so everything is fine there. If it helps the HD is formatted as "MS-DOS (FAT32)" and the USB stick is "MS-DOS (FAT16)". I don't really know what to do because I have never had this problem on the same computer with Snow Leopard in the past (the only time I did was when the file was too big to copy onto it because of the formatting or something but it definitely isn't the case now). PLEASE HELP!