I use my Lenovo twist for work. From time to time I have to assign a static IP address to my network card based on the customer premise. What I have found is that if I do a ipconfig from the command line, these static ip addresses are not released.
If I assign ip1, then customer site ip2, customer site ip3, all three ip addresses will show up doing an ipconfig from the command line. From time to time, this also plays havoc with my wireless network card.
The only way I have been able to resolve the issue is to remove the device(s) and reboot.
Upon reboot, both devices are back to dhcp and normal.