Supermicro(dual core) server getting rebooted after "decompressing the kernel;booting the kernel" me

supermicro(dual core) server getting rebooted after "decompressing the kernel;booting the kernel" message comes.
I tried giving acpi=off to the kernel command line but same problem.It shows everything ok and no problem with memory and processors and power supplies.Wt could be the reason?
It has got 2.6.9-ELsmp kernel and is been in to production from last 3 yrs w/o any problem nor any changes made to it.

This server was working for the previous 3 years with this kernel? I think either the kernel file's been corrupted, or your computer's memory's gone bad.