Fedora Server Crashing

[Bill Polhemus]

Ki Song wrote:
> My Fedora Core 4 Linux Box (primarily used for a mail server: postfix) is
> crashing 3-4 times a day!
>
> I looked at the messages log and I see the following unexplainable record in
> the log file:
>
> crond(pam_unix)[22601]: session closed for user root
>
>
> Is someone trying to login to my server as root?
>   
No, that's a pretty common "extra verbose" log entry. Can you give more 
particulars about the "crashing" phenomenon?

If this is just "random crashing" while it's sitting there, offhand I'd 
suspect a hardware problem.