[SciPy-user] Least Squares error message.

Hi all, I'm trying scipy.optimize.leastsq routine and I get the following warning message as output:

In [100]: lstSquareEstimate Out[100]: (0.029000567127575108, 'Both actual and predicted relative reductions in the sum of squares\n are at most 0.000000')

The message doesn't seem too much explicative (at least to me), and even after looking at scipy and MINPACK source codes, I've not got any further insight. Could someone try to explain what was going wrong here? Thanks in advance, Andrea.