This is known to occur on IBM ESX host servers with 6 core CPUs. The configuration tab for the host will show the correct number of cores, but will incorrectly double the number of processor sockets. For example, a host with 4 CPUs having 6 cores per CPU (24 cores in total) will be displayed as 8 CPUs having 3 cores each. This behavior can cause problems with software licensing as this is often done per physical CPU socket.
Enter the BIOS on the ESX host. Go to Advanced Setup - CPU Settings. Switch the cluster setting from Logical to Physical.
For more information on this issue please refer to http://communities.vmware.com/thread/299101