Alright, recently I've been playing xbox live with a few friends, all forming parties and having a generally good time. Unfortunately I've been having the strange problem of not being able to connect to Canadian xbox live players. At first I thought it was my NAT type, it was moderate, so I went into my router and changed the settings so that my NAT type was open, I thought the problem would be solved. But alas not. I've been able to connect to American players I'd been having problems with before, but I still have no luck connecting to Canadians, and they can't connect to me.

Does anyone know what this problem could be or where I can go to get help with this problem?