Snow Leopard somehow got out of whack. Have been to the Apple Store twice in the past two days. They replaced the hard drive saying that fixing the OS was too complicated but that didn't work. They reinstalled Snow Leopard and it was running fine. Now though, I receive a message saying that the startup up disk is almost full. It's a 320 GB hard drive and Finder says that I only have 287 MB (MB, not GB) available. But, I haven't installed a single thing since I just got the MBP back today. The only thing on the computer is the OS and the including applications. Any idea how to fix this? Thanks.