VS2010 Debug and Release Clean and Rebuild

VS2010 Debug and Release Clean and Rebuild

I have one project (in c/c++ ) which consist of two solutions. First one
is "build_model", another is "fit_model". I set up properties to put all
binaries in the same directory as "fit_model" will invoke during it's
execution "build_model".
So, I first compile "build_model" and it goes well. All files are put into
.../bin\ Then I compile "fit_model" and it is OK as well. All files are
put into .../bin\ Everything works fine. Even if do "Clean" and "Rebuild"
for "fit_model" only it's binaries are deleted are re-created. That is for
Release build. Clean & Re-build of "build_model" also cleans only it's own
binaries (as it should be).
But when I switch to Debug mode, as soon as I do Clean for "fit_model" it
deletes all of the binaries in .../bin\ folder, including it's own and
binaries from "build_model". This is NOT what I want.
So, this is not happening in Release, but only for Debug clean & rebuild.
The problem is that even with different directories it does the same.
Which settings should I change? (VS2010, Windows7)