This happened to me a couple times now. I would finish a fight stage, claim the rewards, tap go to map, and get disconnected from the server. But that's not the only thing. This occurrence disconnects my 4G. Turns it off entirely, then back on, sometimes taking a full minute for it to come back on with just phone service being available and no internet. It just happened a third time just now today after killing Dupre, but it happens with different levels and not the same one. I'm sure it's DL doing it because I was playing and nothing else was using the internet.

I think this happened at least once after claiming rewards on a non-fight stage, too.

HTC My Touch 4G (Glacier), Android 2.3.4