Arngeir flags a shout location at Arcwing point, however after wiping it out, and receiving the shout language, the quest never flags as complete. Therefore, I can't get any further shout locations from Arngeir.

I've tried starting from a clean save from right after I installed Dawnguard and I will got the same issue.

I also attempted to clear the Soul Tear shout quest(as it was active at the same time), thinking that it may be due to two shout quests(complete conjecture), and the issue remains.

Anybody else have this issue?