链接问题

--------------------Configuration: WebServer - Win32 Release--------------------
Compiling...
Main.cpp
WebServer.cpp
Linking...
WebServer.obj : error LNK2005: "int __cdecl `anonymous namespace'::power2bits(int,int,int)" (?power2bits@?%D:/ACE_wrappers\ace/Timer_Wheel_T.cpp1371812758@@YAHHHH@Z) already defined in Main.obj
Release/WebServer.exe : fatal error LNK1169: one or more multiply defined symbols found
Error executing link.exe.

WebServer.exe - 2 error(s), 0 warning(s)
程序中绝对没有出现上面的命名：power2bits(int,int,int)。到底是什么原因出现这种错误呢。