Strange "Previous Definition Different" error

[zuroc]

I create a new project with IDE poseidon and the lastest DMD2.
Complie below code with option "-g"

But a strange "Previous Definition Different" happend.
I don't why ? Who can tell me , thanks :)

Code:

import std.c.windows.windows, std.c.windows.winsock;

static this(){
	WSADATA wd;
}
int main (){
	htons(9001);
	return 0;
}

Complie Information

Command >>> ReBuilding Project: stalk......
D:\myWay\env\d\env\dmd\bin\dmd.exe D:\myWay\D\stalk\stalk.d -ofstalk -
ID:\myWay\env\d\env\dmd\import D:\myWay\env\d\env\dmd\lib\WS2_32.LIB -
odobjs -g

D:\myWay\env\d\env\dmd\bin\..\..\dm\bin\link.exe objs\stalk,stalk,,D:
\myWay\env\d\env\dmd\lib\WS2_32.LIB+user32+kernel32/co/noi;

OPTLINK (R) for Win32 Release 8.00.1
Copyright (C) Digital Mars 1989-2004 All rights reserved.
D:\myWay\env\d\env\dmd\bin\..\lib\phobos.lib(winsock) Offset 2597FH
Record Type 00C3
Error 1: Previous Definition Different : _htons at 4