Dungeon Problems (PS3)

I am on PS3 version and here are three issues in Dungeons:

1) Other Players in my party will disappear on my screen. They are still there playing but i cannot see them or target them for the duration of the dungeon run.

2) Lag! There is tremendous lag going on which makes me worry about ever playing a healer and/or Tank type class. which leads into number 3.

3) Any Tank that is playing through Brayflox cannot Tank the last boss because of lag. I've had several runs with PS3 users who were tanks and could not evade Dragon's Breath move.

Please make dungeons less glitchy on PS3. They are, at times, unplayable.