Redmine

Hello All,
I have installed redmine on Ubuntu 10.4LTS. The following are the version details
Redmine-1.4.2
Ruby-1.8.7
Rails-2.3.14.
I have installed Mongrel.
I have migrated the DB from redmine development to Production server. On migration I did not receive any errors. I have 4 projects(parents) and their sub projects created on dev. server. I am able to access and view all the issues both on parent and sub project in dev. instance. On migration to production server, on click of Parent Project I am not able to view the issues. I am being displayed with the error mentioned below:-

ActionView::TemplateError (No route matches {:project_id=>#<Project id: 1, name: "Sample Parent Project", description: "", homepage: "", is_public: false, parent_id: nil, created_on: "2012-05-07 17:01:30", updated_on: "2012-07-20 11:32:08", identifier: "sample", status: 1, lft: 1, rgt: 2>, :controller=>"importer", :action=>"index"}) on line #57 of app/views/layouts/base.html.erb:
54:
55: <% if display_main_menu?(Herve Harster) >
56: <div id="main-menu">
57: <= render_main_menu(Herve Harster) >
58: </div>
59: < end %>
60: </div>

lib/redmine/menu_manager.rb:150:in `render_single_menu_node'
    lib/redmine/menu_manager.rb:102:in `render_menu_node'
    lib/redmine/menu_manager.rb:91:in `render_menu'
    lib/redmine/menu_manager.rb:168:in `menu_items_for'
    lib/redmine/menu_manager.rb:165:in `each'
    lib/redmine/menu_manager.rb:165:in `menu_items_for'
    lib/redmine/menu_manager.rb:90:in `render_menu'
    lib/redmine/menu_manager.rb:80:in `render_main_menu'
    app/views/layouts/base.html.erb:57
    app/controllers/projects_controller.rb:168:in `show'

Rendering /var/www/redmine/public/500.html (500 Internal Server Error).

Im able to view the sub projects all features.
On creation of a new project on the production server, and its sub project. I am able to view both the newly created Project issues and its features and its sub project features too.

I have installed the plugin redmine_importer plugin. Later I have uninstalled the plugin.

Can any one provide their valuable suggestion to resolve this issue.

Regards,
SR.