In the UESP, it says that one way to avoid the conflict and still be in both guilds, assuming you've already joined both guilds, is to taunt Sottilde and kill her, take the book back to Eydis, and bam, all is good. But all is not good. After finishing all of Eydis' quests, I went on to the Imperial Legion, and have finished all of Darius' quests. Now I come back to do the Balmora Thieve's Guild quests, and while I can get the quests, I cannot advance. Every time I click advance, I get the usual line about nobody questions your skills, but some question your loyalty, perform more jobs for your brother thieves.
Is this the way it is? Is this what's causing it? Is it because I taunted and killed Sottilde for the code book that I now cannot advance in the Thieve's Guild but can still do the jobs, or at least Habasi's?
If so, that's odd that it didn't mention anything about that on UESP. According to it, you should be able to go on about your business like nothing ever happened.
And the really weird thing is that I don't remember this happening before. Granted, it's been a while since I've done a character that has joined both the Fighter's and the Thieve's Guild, but I certainly don't remember this happening, and I'm pretty sure I did it the same way last time.
It's too late now, as I'm not going back and redoing it, as then I'd have to redo most of Eydis' quests and all of Darius' quests, and that's just not happening. I'm to a good point in the game and am enjoying it where I'm at...actually starting to really get into the character.
So, I guess this is really just curiosity about the cause of this particular problem. I have no intention of fixing it, unless something can be done by console. Either way, thanks in advance for any answers.
EDIT: Hmmmm, oddly enough, after doing the dwemer artifiacts quest for Sugar-Lips Habasi, I was finally able to advance from Toad to Wet Ear. Odd that it took 3 jobs to advance to Wet Ear when it normally takes just the 1st one. I wonder if THIS is because of what I did with the code book?