I have a VS.NET 2003 solution of many small-to-medium .cpp files, say

file1.cpp
file2.cpp
file3.cpp
...
file15.cpp

Each file includes many large STL headers, string,vector,list,map, etc.
This causes the build to be very slow when each file is compiled individually.
I'm trying speed up our build by creating a new file
"composite_file.cpp", which is simply

#include "file1.cpp"
#include "file2.cpp"
#include "file3.cpp"
.......
#include "file15.cpp"

I added "composite_file.cpp" to the VS.NET 2003 solution, and
set "file1.cpp-file15.cpp" to "Exclude from Build" in their solution
property settings.  
This builds much much faster, except that the dependencies have stopped
working.   When I modify "file1.cpp", VS.NET 2003 does not rebuild
"composite_file.cpp" when I do a "build solution".

Where are the VS.NET header dependencies stored for a .sln file, and how can
I view/add to them or force them to be regenerated?  I'm suspecting the .ncb
file.

I would rather not merge file1.cpp-file15.cpp into one huge file because
that will
increase source control merge conflicts and be less manageable.  We're not
using
precompiled headers because I've found they introduce hard-to-solve bugs
that magically disappear when you dont use them.