The issue with nan -> 0L was fixed in Python 2.6. I can't recall if I
fixed it or somebody else but I know it was discussed.

$ python2.6
>>> long(float("nan"))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: cannot convert float NaN to integer
>>> long(float("inf"))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: cannot convert float infinity to integer