I did a brief search to see if this topic has been covered but there's a lot to wade through right now so I apologize if I'm hitting a bug that's already come up.

I went through lag issues for about a day then they cleared up completely on their own. Now I'm experiencing a very frustrating problem. As I finish quests (for example The Only Cure, after killing the character I'm supposed to kill) the quest no longer triggers as complete. Now when I go to new quest givers they will give me dialogue about quests but then the game will not allow me to accept the quest only back out of dialogue. Even worse I cannot trigger the barter menus with any merchants.

At one point this problem seemed to clear up, giving me seven or eight dialogues and merchant screens at once even though I was across the world map from the people I spoke with. Then the game worked fine for a while before the problem returned only this time effecting my quests as well as bartering.

I am at level 25, have a 12 mb save file.