Oke, but I wood not recommend people stuff based on the way some compilers "that are shitty and dont conform to the ANSI standard" work, surely not when you dont know or the OP is using such a compiler.
But that doesn't have anything to do with the header (or maybe it does. I remember VC++ 6.0 used the .h headers and didn't have the std namespace). Using full namespaces is more a matter of personal style and a way of avoiding possible future conflicts rather than compliance with the standard.
My point is that you recommended someting with the purpose to avoid possible bugs, in the case that the code would be compiled with comilers that dont conform to the ANSI standard.
That's like recommending a writer of romances: "Dont use difficult words, because the translator may not know them!"