The only problem with this which I found inaccurate after tests, not sure if it's a platform specific, but http://uesp.net/wiki/Oblivion:Temple_of_the_Ancestor_Moths_(place) it says if you http://images.uesp.net/0/0b/OB-map-Temple_of_the_Ancestor_Moths_Exterior.jpg you'll trigger the quest prematurely whether you're in the TG or not however there is no D door in that area. the D is showing you a group of rocks that supposedly there's a hidden door that accesses something but on the PS3 GOTY edition it's not there. And since I tried entering the usually way i never triggered it after 4 attempts. So i believe UESP might be wrong when it comes to this information because i had no TG quest pop when going in about gray fox wants to see me. Or is this particular only shows up after the fact and in the imperial city?
edit: seems i was mistaken, talking to methredhel seems to triggered the bug on my 5th test. Weird. lol