installation (python/libc6) broken, but how?

[Johan Grönqvist <johan.gronqvist@gmail.com>]

Hi,

The three-line python program

import numpy
m = numpy.random.random((16, 16))
(x, v) = numpy.linalg.eig(m)

runs fine in my chrooted sid, but in my (main) squeeze installation it 
produces
*** glibc detected *** python: free(): invalid next size (fast): 
0x0000000001407890 ***

In squeeze, I reinstalled python-numpy and upgraded libc6 to unstable, 
but I still get the same error.

Thanks in advance for any help on how to diagnose this.

/ johan