Is there a BIOS update available for your server? Sometimes those can cure such problems.
Also, is your CentOS updated? What version of CentOS you have, anyway?
Disabling ACPI can be done by passing acpi=off
parameter to GRUB kernel line in the boot screen. Just press e in GRUB at your current kernel to edit the boot parameters, then move to kernel line and append acpi=off
at the end of that line. Then just press enter and then b to boot.
That change is just temporary and will last until you reboot the server next time. Should you want to make the change permanent (I doubt that...), just edit /boot/grub/menu.lst
.