Ok i dont know if anyone else has encountered this but (as i have stated in my support ticket) my party had 2 cases that the instance just wouldnt delete after finishing.
One was at an Extreme Freya that even though we finished instance and all people left we could still see in /instancezone the "Ice Queen's Castle" instance "In Use" for approximately 2,5 hours after we all left and noone stayed inside
Second time was Last night when my party finished Epic Spezion and we left the Instance we could not enter in any other instance (party or solo) because "we had entered another instance dungeon" as the message said, this time though the /instancezone was clear to all 7 people of the party but again the same message was showing on any attempt to go into an instance (party or solo)
Anyone else having same issues? maybe we could provide NC with some more info to clarify this as a bug or just one-time (actualy 2 times) case