Code review comment for lp://staging/~gary/launchpad/bug403618

This branch fixes a misconfiguration discussed in bug 403618. It does not add a test because the example shown in the bug report does not duplicate the problem, because the problem is an extreme edge case, and, generally, because I believe the cost of writing the test would be much higher than the benefit, and I've gotten salgado and flacoste to agree. :-)

The branch passed ec2 already.