10 minutes to re-connect to network after switching switch ports

I'm experiencing long delays in reconnecting to the network when I move the network cable that a PC is using from one port on a switch to another port. The delays are about 10 minutes.

Here is a desciption of the problem.

PC one configured with a static IP of 192.168.0.3 is plugged into port 3 of a cisco SG500 switch.

PC two is configured with a static IP of 192.168.0.4 and is plugged into port 4 of the switch.

On both PCs, I start a ping -t.

Then I move the network cable from port 4 to port 5 of the switch.

As soon as I move the cable, pings on both machines stop working. After about 10 minutes, the pings start working again.

[While I don't normally move workstations from one port to another all that often, we're implementing VMWare. This same problems occurs when we use vMotion to move a VM from one host to another -- the host loses network connectivity for 10 minutes.]

Any ideas on where to look?