Kernel Panic - Not synching Machine Check

[topgun9 at gmail.com (Vikas)]

This server was running fedora core 2 till 12/2/2005. It had an
impressive uptime of 180 days or so. On friday I upgraded to CentOS
4.2. After upgrading to CentOS 4.2 this server has been throwing
kernel panics every 10 hours or so.

These are some of the error messages I am getting on the console:
"CPU 0:Machine check exception :4 Bank 0 : f672100000000833
TSC 112180365ccf ADDR e2c7f7c0
Kernel Panic - Not synching  Machine Check"

This is a production server. I would appreciate any help.

S