I have had the Mifi 4510L for a few months now and when I bought this product I was told that even though my area only supports 3G at the moment that I should have no problem connecting to Xbox Live and playing.
My first problem is the NAT setting, I am unable to get into games because of my NAT is set to moderate. My second problem is that I can get into a game and play if someone invites me to a game instead of searching but after a few minutes of playing the Mifi disconnects me from Xbox Live. So, if I do get into a game I have a few minutes of playtime then I'm kicked out. Is there any way of solving these issues?