Observing Marco's posts from the past, I think he understands that there is no
unique solution.
I think the question was rather given that Octave and Matlab both claim
to use the same LAPACK routines they come up with different (though
equally valid) solutions. Matlab uses the Intel Blas/Lapack libraries
and Octave is probably using Atlas so the difference is probably in the details of the implementations of these libraries.
D.
In fact, Octave built using Apple's vecLib gives the same result as "the other
program" ;-)