To test if your Lapack is broken type this in your python interpreter:
from Numeric import * from LinearAlgebra import eigenvalues x = array([[1,2],[3,4]]) eigenvalues(x)
There are several possible solutions to this problem. First try to rebuild Numeric after setting a compiler flag:
CFLAGS='-ffloat-store' python setup.py build
See: http://starship.python.net/pipermail/mmtk/2006/001097.html (Thanks to Anders for pointing this out)
If this doesn't work, the best strategy is to rebuild Numeric against external Lapack/Atlas libraries: See Lapack & Atlas !