User blog:Corner-Law-gic/Vingalmo bug help?

I play the Xbox 360, and I've been having a little problem of mine...It seems that vingalmo is not giving any new volkihar quests which stops me from having any more Volkihar radiant quests. Reloading saves isn't optional, because this was far too long ago when this problem started, and I don't know how to fix it. I've done 2 of his quests, where you infect a named NPC, however he has not given me the option to give me a third one (infecting Valindor in Riften). He is the only NPC that I can't say "What can I do to help" to, while everyone else in Volkihar links me to his non-existant quest, while a marker sits above his head. I've tried hurting him, killing the previously infected vampire NPCs, even killing Valindor, but none of these helped him pass me a quest, but I didn't save the game after these attempts. Any help?