My late 2008 15" MacBook Pro has been taking a lot longer than usual to start up and shut down (lengthy spin wheel cycles). It is completely up to date with Snow Leopard and I almost never download 3rd party software. I pretty much only use the included iLife apps and a bit of iWork, so I'm not sure what could be slowing the process down. I was thinking I could reinstall Snow Leopard, but I was hoping some tech savvy folks on here could provide a quicker solution. Any ideas?