Beth isn't going to fix it.
In that case, if I knew this, I wouldn't buy this game!! I must watch out for skyrim, too. Beth release software with bug and wont fix.
You could try removing shivering isles, and see if the quest will complete that way, you will lose any progress in SI though. I think.
It is GOTY edition, where after inserted into PS3, everything is there.
I don't see any options that I could select "do not install shivering isles" or "remove shivering isles".
Yes, definitely all SI ruin.
Here is my story.
As soon as I got King Amulet and out from prison, "A Door in Niben Bay" pop up in journal. Then, I've done a few other oblivion quests and, when I was doing "Caught in the Hunt" in Fort Grief, and since nearby, I happened to check out "A Door in Niben Bay" journal entry. But I didn't know that it would enter SI. After talked with Haskill, I realize I was in SI. Anyway, I keep continue inside doing "Through the Fringe of Madness". At the same time, I killed NPC on way, got strange matrix and "The Antipodean Hammer" quest in journal. After I managed to kill gatekeeper, I decided not to continue in SI as I wanted to do more in main Oblivion quests, so I went back to Cyrodiil for main oblivion quest lines.
As fun as keep going, one day I contracted Porphyric Hemophilia and become vampire. Then, started cure vampire quest and stuck at bloodgrass. After not much choices left, I googled and, found others' complains and UESP wiki entry to switching PS3 system language fix. After I did that I can cure vampire. But "Through the Fringe of Madness" and "The Antipodean Hammer" journal entries are vanished and "A Door in Niben Bay" pop up in journal again. I just thought it would just restarted all SI quest line. But...
And then, I was on mission for "The Lonely Wanderer" and go into Tiber Septim Hotel and found that two strange NPCs are (aftermath, i realize that Priest of Order) killing everyone as soon as I enter into hotel. I realized that I'm screwed and quickly go and check the strange door and I can't go in SI any longer with message saying "the door will not yet open to you".
.......
So, if happened to enter into SI and, do cure vampire latter with PS3 system language switch fix does not really do the fix, yet!!
.......
So, what to do to eliminate this two Priest of Orders?
- Save your game before enter into Tiber Septim Hotel, and don't enter it.
- Go to "A Door in Niben Bay"
- Switch back again PS3 system language into French (or the language that you used during cure vampire)
- Then you can enter into strange door but you will end up elsewhere of SI locations (to me, i ended at Fetid Grove, Encampment)
- As soon as you entered, just save with new save slot (in French)
- Then, quit game, switch back PS3 system language to English and load your save slot from previous step
- Loading........ and Woop! you are inside Tiber Septim Hotel!!!
- And now you check around, there is no more Priest of Orders around in hotel as well as in the city (at least that what happened to me)
- After you wait about 1 or 2 hour, "A Door in Niben Bay" will pop-up again in your journal. Just like after cure vampire quest.
........
So, does it mean fix?
No, no, the good news is at least you can continue Cyrodiil for main oblivion quest lines with that character. But probably all SI quest lines are screwed up.
I'm still experimenting now for how to continue in SI. But this is nut as this is obviously software bug!!