mx.DateTime bogus warning: "float where int expected"

[python]

Hi-
I'm getting a "DeprecationWarning: integer argument expected, got float"
warning with mx.DateTime and I can't figure out why. Can anyone help me
out?

This code:

import mx.DateTime

class xLabeller:
def __init__(self, firstdate,fmt='%B, %Y'):
self.firstdate = firstdate
self.fmt = fmt
self.mm = mx.DateTime.RelativeDateTime(months=1)
def __call__(self, i):
dt = self.firstdate + self.mm * int(i)
return dt.Format(self.fmt)

nov99 = mx.DateTime.Date(int(1999), int(11))

xl = xLabeller(nov99)
print "xl2:"
print xl(int(3))

Produces this warning:

================================ RESTART ===========
xl2:
C:\Python23\lib\site-packages\mx\DateTime\DateTime.py:585:
DeprecationWarning: integer argument expected, got float
return DateTime(year, month, 1) + \
February, 2000

What is the story? I've wrapped every number in my program with int(). I
can't figure out what's triggering the warning.

And, even stranger, the whole thing works fine at the python shell:
import mx.DateTime
mm = mx.DateTime.RelativeDateTime(months=1)
nov99 <DateTime object for '1999-11-01 00:00:00.00' at 98dc20> dt = nov99 + mm * 3
dt.Format('%b, %y') 'Feb, 00'

What am I doing wrong?
Thanks for the help.