This happens because your IP address changes while you are viewing the forum, so our system thinks you are logged in on multiple computers.
This has become more common recently as the IPV4 address table has been totally used up and IPs are often reassigned by ISPs on a short lease.
Windows 7 Pro, Intel i7 3.8 GHz (Passmark: 9021), 16GB DDR3, NVIDIA GTX 780 4GB Superclocked (Passmark: 8056)