Make sure in the plugins area that the "Load Modules" plugin is enabled in the Content Group. If you click into that plugin, you'll see the syntax to use, which I believe you have correct above.
I haven't used that plugin in Joomla 1.7 much, but have a lot of experience with it in Joomla 1.5. You may also want to check the module configuration to make sure it's set to show on 'All' menu items.. which, since that's a non-standard position, it still won't show normally unless you've specifically included it using the loadposition tag.
Hope that works, and let us know either way!
Thanks,
Alex