By all means try using a proxy, but in my experience if you visit an IP site like:

http://www.ip-adress.com/

Your IP still remains the same even though it's supposedly changed.

The ONLY way i've succeeded is with a program called HMA Pro VPN:

http://hidemyass.com/vpn/r5018:4/

There are bound to be others available that DO work as well, and DO change the IP when you visit the "check my IP" sites. The downside of this is, depending on what country your "new IP" is situated in, there will be a slower browsing and download speed.

Good Luck !

MOD: por favor, no revivas hilos antiguos.