If you have not finished the companions quest line then I strongly advise you to stop reading now.

Ok...So I completed the companions quest line probably 60-70 hours back in to my first play through ( have around 110 hrs in now )

I decided to go check out somethings at the companions guild since I have been roaming around,exploring and doing misc. quests here and there etc.
so I go to the living quarters in the lower level,search some rooms when I come across one of the rooms at the end,there sleeping in his bed is Skor!!! alive.....lol.

I have no clue how the hell this happened...I'm thinking well he is a werewolf!,he must of supernaturally regenerated his lower half or something!

a few hours afterwards I also ran into two of the same npcs,identical names/looks,said the same lines etc. I have never come across any kind of bugs like this in over 100 hrs of gaming as I prev. sated.
eta: I did not dl the recent update either,so that is not the issue.

Has anyone else exp anything like this!? lol

Just today I went snooping around the building and found him dead on the floor of his room. I was like "What the fu-?!"

I first found him dead on his floor.. Thought that was weird, but continued questing. When I came back he was walking around like nothing happened and called me a whelp! So I shoved my greatsword through his spine and nobody cared. But now ever time a Companion walks past him they yell "I'll find whoever did this!". haha

lmao
well I am at least happy to know it is not just me that has experienced this then.
he called me a whelp as well! haha

btw,the "twins" experience I had was outside of whiterun stables,someone if they can remember to check should take a look there and see if you notice a duplicate of this one guy that I cannot remember his name for the life of me,I want to say his last name is jones, he is bald on top with long gray hair,a bald mullet looking npc.

besides a waterfall not rendering and the prev. mentioned bugs I have been pretty fortunate with Skyrim as far as bugs/glitches go thankfully,I hope Bethesda can get a proper fix for all of us so that we can play without fear or anger as it was meant to be played.

At least 20 levels after he died I found him sitting happily in a chair calling me a noob.

After he was laid to rest I found him few days later levitating, naked, in the middle of the field with other companions (who behaved normally). Couldn't talk with him or anything. It was just his funeral model, levitating around.

I have that duplicated guy also.

Yes, it has happened to me. I posted the same issue in the Hardware section of this forum, reporting it as a bug. I also found a few other posts from people around the net with the same issue. It happened when I was at 136hrs. I am now close to 200 hrs and he still appears. He is able to offer me quests but I am not accepting any. I am afraid if I do, it may seriously break my game. BTW, after Skjor returned, I started having weird glitches and frame rate drops on the Xbox 360 version. it may be a coincidence since that was also around the time when my save file was above 11mg.

Skjor is alive in my game too, and this is after completing the companions critical quest line. Yet another bug in the game. It had been a while since I went to Jorrvaskr so I went inside and there he is on the left side of the main room as I entered. I got a quest from Vilkas to kill a dragon, in my case it was at Mount Anthor. We go there and there is no dragon there, even though I can see the quest marker, NO DRAGON! I take him to a few other dragon locations, we kill the dragon there, even killed a few random dragons, go back to Mount Anthor, *NO DRAGON*. SIGH