[web2py] routers only exposing default controller

[Plumo]

I am mapping apps to different domains using this snippet from the book:

routers = dict(
  BASE  = dict(
      domains = {
          'domain1.com' : 'app1',
          'domain2.com' : 'app2',
      }
  ),
)


I found this only exposes the default controller for each app - how to 
access the others?

Richard