Platform: Windows 7
Date & Time: May 11, 2011 15:00 GMT+1
Frequency: Always (However I did not start over the quest to see if it happens again. The mushroom I had to use for it was a pain to get, and I'd rather not have to find a new one!)
Character Name: Efrye Stellaire
Race: Wildwood Elezen
World: Rabanastre
Class/Skill Rank: Culinarian rank 38
Physical Level: 50
Area and Coordinates: Limsa Lominsa (6, 4)
Party or Solo: Solo
Quest Name: Something in the Soup (culinarian's quest for rank 36)
NPC Name: Prudentia

Steps:
  1. I completed the quest up to the point where the player has to synthesize a "Foulbelly Meatball". At this point I had to leave the instance in the culinarian's guild to get one of the necessary materials ("button mushroom").
  2. After returning to the instance and creating the Foulbelly Meatball, my journal did not update and none of the NPCs within the instance had anything new to say. Opening the map from my journal still points me at the culinarian's guild though, even though there's apparently nothing to do there.
  3. Going from the story of the quest, I'll probably have to speak with Prudentia, however she only appears inside of the instance and is out of reach. If I go near her, I leave the instance and she disappears.
  4. Here's a screenshot of the situation: http://npshare.de/files/20013fd3/Capture.JPG