Deleting natives file.

Upon shutdown of Minecraft I get a warning about failing to delete natives.

snip (normal Minecraft starting/closing no errors)
[09:51:37 INFO]: Game ended with no troubles detected (exit code 0)
[09:51:37 INFO]: Deleting C:\Users\Osky2918\AppData\Roaming\.minecraft\versions\1.6.4\1.6.4-natives-1937786569312
[09:51:37 WARN]: Couldn't delete C:\Users\Osky2918\AppData\Roaming\.minecraft\versions\1.6.4\1.6.4-natives-1937786569312 - scheduling for deletion upon exit
END

There is not that big of a deal but here is what I think is wrong.
I have my game dir outside of /.minecraft/ so something is not correct, it should be able to delete the files...