Using Microsoft Visual C++ 6.0
Dialog based MFC application
I get:
MMTimer.cpp
C:\...\brstt\MMTimer.cpp(26) : fatal error C1852: 'Release/brstt.pch' is not a valid precompiled header file
when I build in release mode. I do not get the error when I build in debug mode.

project settings for debug mode:
/nologo /MTd /W3 /Gm /GX /Zi /Od /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /D "_MBCS" /D _WIN32_WINNT=0x500 /FR"Debug/" /Fp"Debug/brstt.pch" /YX"stdafx.h" /Fo"Debug/" /Fd"Debug/" /FD /GZ /c

Project settings for release mode:
/nologo /MT /W3 /GX /O2 /D "WIN32" /D "NDEBUG" /D "_WINDOWS" /D "_MBCS" /D _WIN32_WINNT=0x500 /Fp"Release/brstt.pch" /YX"stdafx.h" /Fo"Release/" /Fd"Release/" /FD /c

Both debug mode and release mode settings are set to "automatic use of precompiled headers" through stdafx.h

I've done a Clean and rebuild All in both build modes.

note: the MMTimer.cpp (and .h) files are files I found on the internet and reused. Therefore they were not created by VC++. It works great in debug mode but I need to compile/link it in release mode too.

Any ideas?
Thanks in advance.