Main Quest - Higher reputation = do Akorithi quest?

[SwedishBerzerker]

For some reason, I always receive letters from the Necromancer factions, first from Morgiah (instead of Lhotun of Sentinel), now from King of Worms (instead of Queen Akorithi of Sentinel). But I could still do Lhotun's quest (the Missing Brother-quest) simply by going to him and talking to him. I want to do the Sentinel-line of the Main Quest because it requires lower levels than the King of Worms-line. The problem is that I can't do the Wayrest Painting quest by just going and talking to Queen Akorithi, she doesn't respond when I click on her. So, I wonder if this is only because of my Sentinel reputation, or if the game won't let me do the Sentinel quests anymore? Will I be able to do the quest if I raise my Sentinel reputation by doing some Knight-quests in Sentinel city?

Thanks in advance!