After installing Centos 6.3, I installed VMware Workstation 7.1.6.

When the VMware services tried to start, the 'Virtual Machine Monitor' failed.

When I tried to start VMware Workstation I got this error: "Could not open /dev/vmmon : No such file or directory. Please make sure that the kernel module ‘vmmon’ is loaded."

I did a 'modprobe vmmon' and got: "FATAL: Error inserting vmmon (/lib/modules/2.6.32-279.11.1.el6.x86_64/misc/vmmon.ko): Unknown symbol in module, or unknown parameter (see dmesg)"

I renamed /usr/lib/vmware/modules/binary to /usr/lib/vmware/modules/binary.old.

Then did 'vmware-modconfig --console --install-all'.  This caused the vmmon module to be recompiled and linked into the kernel and now the Virtual Machine Monitor starts and VMware Workstation functions as expected.