VmWare-Workstation 7 - Could not open existing VM

After the installation of VmWare Workstation 7 I had to adjust something:
I just tried the following:

- Open a virtual machine or team

- Pointed it to an existing WinXP.vmx

- The Tab for the VM was created but when I tried to start it I got the following error:

Could not open /dev/vmmon: No such file or directory.
Please make sure that the kernel module `vmmon' is loaded.

# lsmod | grep vmmon
returned nothing, so I had to load the module:
# modprobe vmmon

After the module was loaded:
#lsmod | grep vmmon
vmmon 87308 0

- I was able to start the WinXP Virtual Machine