So I've recently added the 4 fences to the Thieves Guild and I was about to finish the main quest line (stopped after Loud And Clear), but then Brynjolf stopped giving me the next quest. Wherever he is, he's always saying "Sorry lad, I've got more important things to do. We'll speak another time.". Does someone know how to fix this and/or if a patch is coming in the next Xbox 360 update?

http://www.uesp.net/wiki/Skyrim:Dampened_Spirits

Mercer is supposed to give the next quest according to the wiki, though here are some bugs that may be associated with the quest:

• If the player breaks into http://www.uesp.net/wiki/Skyrim:Honningbrew_Meadery before receiving this quest, it will not become available http://www.uesp.net/wiki/Skyrim:Loud_and_Clear.

• If the player approaches the nest in the first person view, the "activate nest" button needed to poison the nest may fail to appear. Changing to the third person view can sometimes resolve this. PC players can advance this manually using the console command setstage TG03 45.

• After completing the quest http://www.uesp.net/wiki/Skyrim:Loud_and_Clear, if the player does not ask Brynjolf why Maven Black-Briar is requesting a meeting, the quest will not become available. Also Brynjolf will not speak to the player, saying only that he has "important tasks to be doing".

• If the player has a high enough bounty, Commander Maio Caius will attempt an arrest instead of tasting the mead, breaking the quest at stage 70.

• When going through the caverns, near some bear traps, there is a tripwire trap. If the player dies and respawns after tripping it, the tripwire will activate the trap again, even though it appears as if already tripped.

• If all options fail for obtaining this quest, PC users can can skip it using the console with completequest TG03, followed by setstage TG04 1. This allows you to continue progression in the Thieves Guild.

Bolded the one that may pertain to you

Bethesda have apparently fixed this issue in update 1.4 due out soon:

"Fixed rare issue where "Dampened Spirits" would not start properly"

To be honest, it's rather common as opposed to rare. Hopefully this update does help. I'd suggest going back to a save before talking to Brynjolf to complete the quest and wait for the update.

I Finished the entire Thieves Guild Story line and side quests with no problem.

I would like to but I did this quest when I was arounnd lvl 10 and now I'm 30. Also, the update seems to be able to fix the glitch, when will it come out?

I think the patch is coming in the next week or two. Maybe they have worked around the issue for players who have already spoke to Brynjolf. We'll just have to wait and see.

It's been confirmed by pc users that the quest automatically starts after you install 1.4 so that is great news and now we can proceed with the guild.

i really recomend everyone whenever you start a quest line to try to focus on that line mainly since its been reported that long time-windows in between quests may increase the chance of bugs ...so in my case when i started the college of whinterhold i went all the way untill all the mandatory quests were completed ...the same with the thieves guild and i had no problems at all for any of those...

I find very funny the fact that once i completed all the thieves guild quest line and i work my ass down (because few of them did a [censored]) to build the guild back up i still get the attitude from everybody ......and vex and delvin still ask where im i going that they have jobs to be done WTF!!!!!!!! you should all Please continue, my good sir. and start showing some respect to the guy who rebuilded your stinky sink hole and instead of giving me jobs you should come to my feet and beg for some jobs from me "the guild master" ...but no it seems im the same insignificant lizzard that went down the cistern when the guild was falling....This is not complaint its just an observation that every time i get down there as guild master no one gives a damn...

I heard about this bug, but thankfully I avoided it, i'm at that Darkness returns mission though, so fingers crossed.