I had the same... but on my PS3

Time: somewhen around 3PM and 9PM CET
Frequency: once each
World name: Phoenix
Character name: Asteria Odina
NPC name: None
Monster name: non for 3PM, no clue for the other anymore
Class/Level: Dragoon Lv35/36
Party or solo: 3PM: solo, 9PM: party
In-game time: 3PM-ish, 9PM-ish
Area and coordinates: I don't know anymore
Steps:
1. at 3PM: walking to destination (by foot not on chocobo); 9PM fighting monsters
2. I don't know about error codes anymore but showed the following both times: Authentification error, disconnected from server message, black screen (no loading sign, music, whatsoever)
3. I forced the game with controller's "Quit Game" to quit but instead my PS3 beeped 3 times and restarted itself (usually QG brings you back into PS3 menu)