DLL speed depends on the caller !!

[YAZ]

Hello,

I have a project that use some number crunching. The project is
composed of :
1- EXE file in borland cbuilder that make a nice GUI.
2- a Kernel.DLL in VC2003 that do most of the number crunching
3- some DLLs compiled with gcc (mingw ) & g77 (fortran) like blas,
lapack, fftw, etc.

A have a function called test_eigenvalues() coded in C++ in kernel.dll.
This function fill a matrix with random values and call the dgeev()
lapack fortran routine to compute the eigenvalues of the matrix. The
function test_eigenvalues() is exported so that the EXE can call it.

I noticed that when I compile the EXE (borland) in debug mode the
VC2003 function test_eigenvalues() run faster.!!
Of course the VC2003 code doesn't depend on the EXE in anyway.
Can you please tell me why the VC2003 dll code speed changes when the
EXE changes from release to debug mode ?

Thank you