Error 10037 in PSP2i

[Anubis1101]

I'm trying to connect with a non-local player over the internet in Phantasy Star Portable 2 Infinity. He's able to join, and it even sends his character data, but once the game begins, he drops out. We've tried switching who's hosting/joining, and playing with ports and other networking settings, but nothing seems to have any effect.

This is what the host's log looks like:


And this is what the join log looks like: