This has now happened 2x for me, both times have been when I am hosting and always on B Rank.
The mission is awoken serpents.

The level loads fine, all goes well until De Rol Le then as we load up the screen freezes on eveyone's end. Eventually the game dumps all other players and leave the party leader at a perma-lock, to where you have to completely reset the PSP.

Just here to spread the word and get a confirm/deny from any others out there who have experienced it.

Also, if anyone can provide me an e-mail to Sega customer support to file the claim I would appreciate it.