Inventory Incorrectly Listed as Full

[Nebu]

Date & Time: May. 15, 2012 1:25 GMT
Frequency: Once (Did not reproduce)
Character Name: Nebuchadnezzar Nabopolassar
Race: Lalafell
World: Balmung
Class/Level: BLM/50
Area and Coordinates: West Shroud (x:17, Y41)
Party or Solo: Party, 8 members
NPC Name: Pukwa Pika
Monster Name: None
In-Game Time: 6:48
Steps:

While talking to "Pukwa Pika" for the "Feast of Fools" quest when exchanging "Unmarked Keystones", any items which fall to your inventory will fail to enter, as your inventory will be listed as full. However my inventory was not full.