Question: I recently flagged a post on SO as "Unclear what you're asking". Afterwards, for whatever reason, I clicked `flag` again and found this:

![enter image description here](https://i.stack.imgur.com/lh7kM.jpg)

Is there any reason it says I've raised a duplicate flag too when I'm positive I have not? Is this a bug? The question, as of 2:56 PM UTC, 11 September, 2013, has only existed for 26 minutes and the flag doesn't exist in my flag history:

![enter image description here](https://i.stack.imgur.com/Lm2re.jpg)

**Note**: There are several similar questions:

* ["You have already raised this flag" Well, not really](https://meta.stackexchange.com/questions/188818/you-have-already-raised-this-flag-well-not-really)
* [No, I haven't already raised this flag (not here, anyway)](https://meta.stackexchange.com/questions/189288/no-i-havent-already-raised-this-flag-not-here-anyway)

The first was never answered and the second is unrelated as it appears the person asking did, in fact, raise the flag they assumed they hadn't raised.

Answer: 
It was deleted by a moderator after being flagged as "It should be a comment".

For users with >=10k reputation it is still [visible](https://stackoverflow.com/a/18673478/1983854). Comments show:

> 
> That should be a comment. Based on his current question state it's
>  impossible to see what's the problem . – Michael IV Sep 7 at 12:54
> 
> 
> i've added some code – Schnizel1337 Sep 7 at 13:05
> 
> 
> got it, i changed the loop iteration order and now it works, thanks! –
>  Schnizel1337 Sep 7 at 13:55
> 
> 
> 

I don't know if it should be undeleted, as it is not clear if it was useful to solve the question.
It seems like a reasonable, though not stellar answer. Three people thought it was good enough to upvote, and it seems to contain useful information. 

I don't think it should have been deleted. 

Here's the full text of the answer:

> 
> Maybe you should post some code?
> 
> 
> Check the memory traversal if you use loops. You should traverse your
>  buffer in the right order, otherwise you may have cache miss at each
>  iteration. If you use nested loops sometimes you only have to switch
>  the x/y iteration order.
> 
> 
> Also, don't read data from graphic memory. It tends to be slow. Only
>  write to PBO.
> 
> 
> Edit:
> 
> 
> It looks like a syncro issue. I'm not sure you need to map pbo at
>  every frame. Check this [link on OpenGL Pixel Buffer Object (PBO)](http://www.songho.ca/opengl/gl_pbo.html).
>  There's also a workaround for stalls which could improve things
> 
> 
>