Unknown exception from "hg serve"

[Niall Creedon]

Found this today at work, duplicated at home.  Both systems run Win XP 
SP3.  Both systems using Mercurial 1.5.1 (no TortoiseHG).  Work system 
doesn't have Python installed, home has 3.1.2.

C:\work\mercurial>hg init repo

C:\work\mercurial>cd repo

C:\work\mercurial\repo>hg serve -port 8002
** unknown exception encountered, details follow
** report bug details to http://mercurial.selenic.com/bts/
** or mercurial at selenic.com
** Mercurial Distributed SCM (version 1.5.1)
** Extensions loaded:
Traceback (most recent call last):
   File "hg", line 27, in <module>
   File "mercurial\dispatch.pyc", line 16, in run
   File "mercurial\dispatch.pyc", line 30, in dispatch
   File "mercurial\dispatch.pyc", line 47, in _runcatch
   File "mercurial\dispatch.pyc", line 399, in _dispatch
   File "mercurial\dispatch.pyc", line 278, in _parse
   File "mercurial\fancyopts.pyc", line 103, in fancyopts
ValueError: invalid literal for int() with base 10: 'ort'