kexec problem on CentOS 5.3

[Josh England]

I'm running CentOS 5.3 on x86_64 platform with kernel version
2.6.18-128.el5 and having issues running kexec.  I've got the kernel
built with CONFIG_KEXEC and CONFIG_CRASH_DUMP, and I'm booting with
crashkernel=64M at 16M, but anytime I try to load a kernel with kexec I get
the following:

Invalid memory segment (nil) - 0x309fff

Did I miss something somewhere?  I will provide any additional
information if needed.

-JE