Apparently there is a major bug involving Vault 11. If you go into Vault 11 before going to the strip and while in there you go to the suicide room and kill all the robots you will fail the Mr. House quest line and be unable to enter the Lucky 38 Casino without being attacked. This means you cannot get the suite to upgrade. I only discovered this nearly 40hrs after I went to Vault 11 while simply exploring. The robots attack you in the vault suicide room so you have to fight back or die. I did not notice which quest was failed after killing the robots, but several people have posted which quest it is you fail.

All i know is that about 40hrs after being in Vault 11 and upon first entering the strip, Victor the cowboy robot greets me and tells me to head to the Lucky 38 as soon as possible. I follow him there and his face turns from cowboy to cop and his corpse is lying on the stairs of the Lucky 38. When we zone in he and two other robots attack us and the whole casino is agro. Apparently killing the Vault 11 robots gets an unknown robot bad faction. I am not sure what quests involve Vault 11, but don't go there unless you absolutely have to and only after you have your suite in the Lucky 38. Hopefully this is a major bug that will be fixed with the upcoming patch since it would be ludicrous to allow players to explore areas that would ruin the main quest line by simply fighting robots that attack you. Either lock Vault 11 until you get whatever quest or have the robots respawn if they are needed for a specific quest.

This has not been confirmed by the devs as being the incident that bugged the Lucky 38, but I did get a failed quest message after killing the robots and others have posted this is the issue. I am not re-doing over 40hrs of the game so I guess if they don't fix it I will have to side with Mr. Yes Man to finish the game and will never be able to get my suite. I reloaded a saved game prior to entering the strip and have been exploring everywhere else I can prior to going back to the strip in hopes the patch will fix this issue before going back to the strip for the first time on this saved game.

Don't go to Vault 11 if you're trying to be friendly with House is more accurate.Someone poked into the GECK and found the turrets are part of the Lucky 38 faction. Easy enough to fix in a patch. Till then PC users can get a fix http://www.newvegasnexus.com/downloads/file.php?id=35210

hmmm.. wierd... i went to vault 11 first before i see house i didnt have any problem. seeing him...

Last I checked, mr. House was a lot of rotten flesh who has a bullet hole in his head when I killed him with my machine. Multiple playthroughs will be needed.

i just killed him with bb gun.. just for fun...

I don't think a patch would help you with this game. I think it would help if you started over. Your save ALREADY has them being hostile to you. A patch won't fix that, it'll just fix the causes of that. You would need a personal patch from the DEV's to fix your save, and I don't think that's something they're really going to do. If you have a PC there may be a console fix for it, otherwise I don't think you'll be able to do anything other than side against Mr. House.

If you have the pc there is a command you can use to reset your faction standing duno what it is tho.

Same thing happened to me, i failed both quests when i killed the robots. But i have another problem that is even more fustrating, i can't leave the vault! After i defeat the robots in the sacificial chamber and i went to the computer, overrid the security lockdown, but now when i go all the way back to the vault door it says "must be activated elsewhere". Ive looked in every nook and cranny in this vault for another computer to activate the door, but i still cant find it. (There is 1 door i can't open because it requires a lockpick of 75).
Please someone help me find a way out of this vault from hell!

Oh dear. I've marked out the door controls for you http://i56.tinypic.com/2wbvk10.jpg