Thanks for the report.  Also applies to 3.1 and 3.2 (and 2.6, but it's too late to fix things there).  I agree that those (int) casts look wrong---I suspect they're leftovers from the big int -> Py_ssize_t switch that happened for Python 2.5.

I've removed the casts in svn revisions 83751 through 83754.  Unfortunately, right now I don't have access to a machine with enough memory to test that this fixes the problem.  Martin, would you be able to check this?  You'll need a Python svn checkout if you don't already have one;  instructions for getting it are at http://python.org/dev