panicing system

[Tom Jackson]

I've got a box that is going down about every other day. Before all this
started it had been up for about 35 days straight.  I've made no major
changes to the system since it was built ( besides patching).  I've
already jumped to a few conclusions that have not panned out.  The
system is running apache/MySQL/ server running RH 7.1.  It never
encounters an outrageous amount of system load.  At the moment I am
stumped.  I've checked the obvious things ( I think ).  

 I guess my question to the list is what tools are handy to see what a
box is up to when it decides to reboot( that may be putting it too
nicely).  Or possibly some tips/tricks on how ferrit out sneaky
problems.  I understand this is a VERY broad subject but any help would
be great.

Tom Jackson
www.syn-packet.com