LinuxQuestions.org - Fedora Core 6, Updating Kernel = Kernel panic

First let me explain my setup.

Fedora core 6 running in vmware on a windows 2k3 system.

In order to install vmware tools i need to update my kernel.
So i follow these instructions.

1. # Install packages to build the kernel modules

yum install gcc kernel-devel

2. # Check the running kernel matches the kernel headers

uname -r # running kernel
rpm -q kernel-devel # installed kernel headers

3. # If the two versions do not match, run

yum -y upgrade kernel kernel-devel
reboot

After doing those 3 steps, i get a kernel panic when trying to boot.
Error: "Kernel panic - not syncing: Attempted to kill init!"

I can boot the old kernel 2.6.17-1.2630.fc6 but the new kernel 2.6.20-1.3084.fc7, gives me the kernel panic error.

I noticed how the old kernel is *.fc6 and the new one says *.fc7, does this stand for fedora core 6 and fedora core 7? I'm running fedora core 6, so is this new kernel only compatible with fedora core 7?