One of the top rules of system administration I learned early on is to always try the simple explanation first, even if you're sure that can't possibly be it. Much of the time the OS/applications are running fine, and the problem is simple rather than some obscure, complex failure condition. How many times have you wasted an hour debugging a TCP/IP problem before you realize you really DO have the IP address wrong, or had DNS give you error messages that you just didn't believe at face value and spent time looking elsewhere for the problem? Always check the simple stuff first!
Bruce