I have this problem too. I switched my location settings to US and it allowed me to play some of the locked games, but didn't do much for unlocking DLC. What I ended up doing (which sucks) is I mailed a USB stick to my uncle and had him recover my gamertag and download the DLC to the USB stick. Then he mailed it back and I copied the DLC to my hard drive. It can be a long process but I'm patient. As soon as I get the data off of the USB I send it right back to my uncle so it is already there for when the next DLC problem comes up, this saves about 10 days shipping time.