ptlib build error

[1024WealthSchool]

while building PTLib DLL,there is an error:
2>ptlibs.lib(win32.obj) : error LNK2001: unresolved external symbol "class PPlugin_PSoundChannel_DirectSound_Registration PPlugin_PSoundChannel_DirectSound_Registration_Instance" (?PPlugin_PSoundChannel_DirectSound_Registration_Instance@@3VPPlugin_PSoundChannel_DirectSound_Registration@@A)

how to fix it? (I'm using win8.1+vs2012)

[gle2135]

I got the same error in VS2005+win7_32; and if I cancel this instance,myphone3 will be compiled however no sound, have you find the solution yet ?