Hi Mike,
Thanks for the help, it turned out to be a silly misunderstanding on my part, the value of the parameter ServiceName didn't match the name of the service class, once I got those lined up everything worked as expected.
How tough would it be to add support for service instances to the install task? I find that I sometimes need to install the same service side-by-side on the same machine, and it doesn't look like I can do that with the extension pack as it now stands.
thanks,
jason