[SciPy-User] problem with optimize.curve_fit

[Luca Delucchi]

Hi everybody i try to use optimize.curve_fit but i have a error

gis@srvcavit:~/meteo_python$ python prova_optimize.py
Traceback (most recent call last):
  File "prova_optimize.py", line 23, in <module>
    popt, pcov = curve_fit(func,x,old_y,2)
  File "/usr/lib/python2.5/site-packages/scipy/optimize/minpack.py",
line 423, in curve_fit
    raise RuntimeError, "Optimal parameters not found: " + mesg
RuntimeError: Optimal parameters not found: Both actual and predicted
relative reductions in the sum of squares
  are at most 0.000000 and the relative error between two consecutive
iterates is at
  most 0.000000

i see that is a bug [0], i try to modify the script with the solution
proposed by kael but nothing change, here [1] you can find the script
that i use, how can i solve my problem?

thanks
Luca

[0] http://projects.scipy.org/scipy/ticket/984
[1] http://pastebin.com/m3c721c6f