drush fails when using a domain with sites.php

OK, so this probably isn't a supported configuration, but I guess that it will effect 7.x-2.x also.

I am running D6 with the sites.php patch #231298: Aliased multi-site support applied. At present I only have the one drupal site, which is in development (cgc.org.au), and a sites.php redirect for the current development domain name (cgcdev.dailyfuneral.net). When I run drush i get the following error:

drush -l http://cgcdev.dailyfuneral.net -r /var/www/html -v help
PHP Notice:  Undefined index:  path in /var/www/html/sites/all/modules/drush/drush.php on line 130
E: Invalid command help.

I'm assuming that it is the sites.php redirect that is causing the issue, but don't know enough to dig into it.

Regards

Jerome