Comment 9 for bug 780220

FWIW, I suspect that the problems with numpy in Oneiric in a virtualenv are due to upstream numpy not being multiarch aware, and thus it cannot find its dependent libraries or headers. Oneric's version of numpy should fix this, though that doesn't help you in a virtualenv. The multiarch problem will have to be fixed upstream in numpy, and it will soon affect Debian as well as Ubuntu.