Custom Module Builder - Display In Group

When I create a new project, how do I get my custom module builder to display in the list with a heading - like Java or Groovy?

I've overwridden the getGroupName() method in my ModuleBuilder :

    @Override
    public String getGroupName() {
        return "Salesforce";
    }

I've tried the following:

1)  Only specify the <moduleType> in the plugin.xml - this causes it to display under the Other group
2)  Only specify the <moduleBuilder> in the plugin.xml - same outcome as #1
3)  Specify the <moduleType> AND <moduleBuilder> in the plugin.xml - this causes the module type to be listed TWICE, but in a "Salesforce" group
4)  Specify the <moduleBuilder> twice in the plugin.xml as a test - same outcome as #3

How can I get my single Module Builder to display under a "Salesforce" group?