Hi, I installed the opesteam 0.9.3, and when I run the script/genarete opensteam
WebShop. I get the follow erro:

emygdio@emygdio-laptop:/var/www/rails_app/shopping$ script/generate opensteam
WebShop
Route segment "(.:format)?" cannot be optional because it precedes a required
segment. This segment will be required.
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:94:in
`interpolation_chunk': wrong number of arguments (1 for 0) (ArgumentError)
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:94:in
`generation_code'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:92:in
`each'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:92:in
`generation_code'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:46:in
`source_code'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:16:in
`generate_optimisation_block'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:142:in
`inject'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:15:in
`each'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:15:in
`inject'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/optimisations.rb:15:in
`generate_optimisation_block'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:178:in
`define_url_helper'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:137:in
`define_named_route_methods'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:134:in
`each'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:134:in
`define_named_route_methods'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:85:in
`[]='
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:317:in
`add_named_route'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:57:in
`method_missing'
from
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/option_merger.rb:20:in
`__send__'
from
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/option_merger.rb:20:in
`method_missing'
       from /var/www/rails_app/shopping/config/routes.rb:25
from
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/core_ext/object/misc.rb:78:in
`with_options'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:51:in
`namespace'
       from /var/www/rails_app/shopping/config/routes.rb:23
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:226:in
`draw'
       from /var/www/rails_app/shopping/config/routes.rb:1
from
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:145:in
`load_without_new_constant_marking'
from
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:145:in
`load'
from
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:521:in
`new_constants_in'
from
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:145:in
`load'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:286:in
`load_routes!'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:286:in
`each'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:286:in
`load_routes!'
from
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.4/lib/action_controller/routing/route_set.rb:266:in
`reload!'
from /usr/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/initializer.rb:537:in
`initialize_routing'
from /usr/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/initializer.rb:188:in
`process'
       from /usr/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/initializer.rb:113:in `send'
       from /usr/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/initializer.rb:113:in `run'
       from /var/www/rails_app/shopping/config/environment.rb:9
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in
`gem_original_require'
       from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
       from /usr/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/commands/generate.rb:1
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in
`gem_original_require'
       from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
       from script/generate:3

Can you help me ? 
Thanks