Crash analysis/possible security problem?

[andrew.hodgson at blueyonder.co.uk]

Hi,

Noting the discussion taking place recently, I happened to be in my room this lunchtime and heard the familiar 'beep-beep' my gateway box issues when it POSTs - it had rebooted by itself!

I promptly SSH'd into the box and used last to see what had happened, and instead of 'crash' I saw 'reboot' - is this something I should worry about? I tried to use who (to see if anyone was logged in - nobody but me) and also checked /var/log/messages to see for logins and other strangeness, but found nothing. 

The box is a rather ropey old 233MMX PC box, so I wouldn't be surprised if it's on its last legs. But, if anyone thinks I should be worried about security then I'd appreciate some help.

Best Wishes,

Andrew