plexus.bat doesn't start Continuum on Windows XP

The getting started instruction tell you to start Continuum by running "bin\plexus.bat" on a Windows machine, but when I tried to run that BAT file all I got was a message "Usage: plexus.bat <xml>". The "bin/plexus.sh" works fine from Cygwin, but the plexus.bat file wasn't passing the configuration argument to Launcher.

If the following variables are added to the end of the :endInit section, the BAT script will start Continuum successfully:

SET PLEXUS_CONF=%PLEXUS_HOME%\conf
SET CONF=%PLEXUS_CONF%\plexus.xml
SET PLEXUS_CMD_LINE_ARGS=%CONF% %PLEXUS_CMD_LINE_ARGS%

I've attached my plexus.bat to this issue.

Is this a bug, or am I just doing something stupid?