Not a member of global namespace?
===

I have the error:
> error C2039: 'read' : is not a member of '`global namespace''
and 
> error C2661: 'Calc::SymString::read' : no overloaded function takes 3 arguments
from the line:
>  if (::read(fd_sock, &size, 4) != 4) 

This error and similar ones appear quite a lot in my code. Does anyone know what the problem could be?
I am using Windows Visual Studio 2010 and I am migrating code from Unix.
Thanks in advance!