VC++ 2008 compiling problem with boost - c++

Question

All of a sudden a two project solution started to fail to compile. I don't remember making any change that could compromise the build. One project is a lib and the other is exe. The lib is still compiling without issues, but the exe fails. I isolated the issue at a point when some boost files are loaded. Here is a the stdafx.cpp that is enough to show the error:
#include "stdafx.h"
#include <boost/thread.hpp>
And these are the errors reported:
1>Compiling...
1>stdafx.cpp
1> c:\program files (x86)\microsoft visual studio 9.0\vc\include\stdlib.h(525) : see declaration of '_ultoa'
1>c:\libs\boost_1_44_0\boost\mpl\size_t_fwd.hpp(23) : error C2143: syntax error : missing ',' before 'constant'
1>c:\libs\boost_1_44_0\boost\mpl\aux_\integral_wrapper.hpp(42) : error C2143: syntax error : missing ',' before 'constant'
1>c:\libs\boost_1_44_0\boost\mpl\aux_\integral_wrapper.hpp(84) : error C2143: syntax error : missing ',' before 'constant'
1>c:\libs\boost_1_44_0\boost\mpl\aux_\integral_wrapper.hpp(84) : error C3211: 'boost::mpl::size_t<__formal>::value' : explicit specialization is using partial specialization syntax, use template <> instead
1> with
1> [
1> __formal=1135
1> ]
1> c:\libs\boost_1_44_0\boost\mpl\aux_\integral_wrapper.hpp(45) : see declaration of 'boost::mpl::size_t<__formal>::value'
1> with
1> [
1> __formal=1135
1> ]
I noticed that if I change the include line to:
#include "stdafx.h"
#include <boost/thread/thread.hpp>
it works, but then I have other includes in the code as:
#include <boost/bind.hpp>
#include <boost/function.hpp>
and they also give the same 4 error lines.
Anyone have any idea what could be wrong? I am restating that this code worked for months and the error first came yesterday.

Answer 1

Hard to guess, but I think there might be some macro defined in stdafx.h that collides with Boost (i.e. Boost uses a variable/function/template/whatever with the same name as your macro). Remember that macros span over scopes. A quick check - does the problem vanish if you change the order of includes?