Added "nmi_watchdog=1" to /boot/grub/menu.lst (Note- " nmi_watchdog=2" did not work):
example:
kernel /vmlinuz-2.6.18-164.el5 ro root=/dev/VolGroupSys/LogVolSys rhgb quiet
nmi_watchdog=1 The "Cannot setup NMI…" message does not appear any more.
Also see the link below for more details on NMI watchdog.
http://publib.boulder.ibm.com/infocenter/lnxinfo/v3r0m0/index.jsp?topic=/liaai/crashdump/liaaicrashdumpnmiwatch.htm