Disk Utility in OS X gave me a Invalid key length after checking Catalog file, so I restarted to OS X Install DVD. It did the same thing on the OS X Install DVD. I went to Startup Disk, changed it back to the Mac OS X on Macintosh HD option - so I could go in and back my stuff up. It just goes to apple logo, does the spin thing at the bottom, and goes black. I can't even boot from DVD anymore. There's data on the drive I absolutely need... any way I can start it up to network it and back things up?