VirtualBox Guest Additions for Fedora 13

Basically, before trying to install the Guest Additions on Fedora 13, you need to:

yum -y update kernel

then

yum -y install kernel-devel kernel-headers dkms gcc gcc-c++

then restart the VM, and THEN install the Guest Additions (which should compile properly now).

After installation of the Guest Additions, you may need to restart the VM once more.