Haukke Manor HM hang - game freezes

The game freezes, BGM keeps playing though

Time: between 7.00pm - 8.00pm
Frequency: tried playing the dungeon 2 times in 2 consecutive days (march 21st and 22nd), always happened.
World name: Ragnarock
Character name: Andres Lonegrief
NPC name: None
Monster name: None
Class/Level: Lv50 SMN / Lv50 WHM
Party or solo: Party
In-game time: unable to verify
Area and coordinates: Haukke Manor (HM)
Steps:
1. The duty starts as usual, then randomly the game freezes. BGM is still played in background, but the game stops, the screen looks like as if I took a screenshot (which I didn't take). It has always happened while I was adjusting my camera in order to have a good view on the dungeon arena. Once the screen freezed, I couldn't log out or exit the game because the joystick wasn't responding as well. The only thing I could do was switching my PlayStation3 off pushing the bottom on my console (which you aren't supposed to do). The Ps3 makes 3bip-sound which signals an incorrect operation. Once I turn the PlayStation3 on again, the system works as nothing happened while it should check the HDD looking for errors or corrupted files (which makes me believe it could be a problem related to the game)

Connection Specs
- cable / service provider; Infostrada (Italy)


Model Number of the PlayStation 3 You Are Using
- Model Number: Slim 120Gb