Windows build broken

AAARGH! Windows build is broken again. Please can someone fix? In file included from rts\RtsMain.c:12:0: rts\PosixSource.h:31:0: error: "__USE_MINGW_ANSI_STDIO" redefined c:\code\head\inplace\mingw\bin\../lib/gcc/mingw32/4.5.2/../../../../include/_mingw.h:280:0: note: this is the location of the previous definition rts/ghc.mk:243: recipe for target 'rts/dist/build/RtsMain.o' failed make[1]: *** [rts/dist/build/RtsMain.o] Error 1