weird symptom - possible infection

[Miles Fidelman <mfidelman@meetinghouse.net>]

Folks,

I'm in the process of building two new servers - each is in a different 
state of software installation.

The thing is, I've had a weird symptom that's now occurred twice:

- at 12:02pm, BOTH servers spontaneously rebooted
- this also happened exactly two weeks ago (12:02pm, 14 days ago)
- as far as I can tell, there's nothing at all suspicious in the log 
files on either machine

The first time, I immediately suspected a power glitch - but I'm in a 
datacenter for reliable power, UPCs per rack, and there was no 
indication of a power event.

This time, the exactness of the two week period makes this look like 
either a lurking bug in some piece of software, or a virus infection. 

Machine 1 is pretty bare bones - not much beyond the basic Sarge 
distribution.
Machine 2 has a lot more on it - I've been building it up - Apache, 
Postfix, working on amasid/etc. right now...

Does this look like anything anybody has come across in the past?  Any 
suggestions as to where to start looking would be really helpful.

Thanks very much,

Miles Fidelman