Unable to finish some Quests

Not sure if i'm the only one who has this problem, but there are two quests that i'm unable to do or finish. Like in Legend of the Snail it won't let me give
the Mano shell to Pia, and in Find Fresh Milk it won't let me go into the stable, no matter how many times i click the response.

I'm pretty sure there might be other quests i can't finish, but those are the only two i have a problem with.

 

http://royals.ms/forum/threads/revised-quest-bugs-list.15140/

 

Quest: Legend of the snail (Part: A Rainbow Snail Shell That Makes Wishes Come True!? )
Location: Henesys park
NPC: Pia
Details: Unable to turn in rainbow shell to complete quest

Quest: Find Fresh Milk
Location: Cafeteria - The Nautilus
NPC: Tangyoon
Details: Was able to accept the quest, but it refuses to transport you to the stable with the cows. More trouble occurred when I forfeit the quest; regaining the quest does not give me the empty jug and the dialog box for teleporting to the stable doesn't appear at all now.

 

Post in that thread, and look for any ones that have already been reported. Both of the ones you listed have been reported already.