51degrees.mobi, Firefox and Javascript error (ASP.NET Webform)

I am seeing some strange behavior with 51degrees.mobi library in my ASP.NET Web Forms web application. I narrowed it down to the simplest test case so you can repro it easily. Here are the steps:

1. Create a new app in VS 2010: File -> New -> Project -> Web -> ASP.NET Web Application
2. Right click Default.aspx and "Browse with" and select Firefox and click "Set as Default"
3. Run the app and notice "Home" and "About" menu items render properly (styled) and there are no errors in Firebug
4. Now stop the app in VS and launch NuGet console: Tools -> Library Package Manager -> Package Manager Console
5. Install 51 Degrees package by typing the command: install-package 51degrees.mobi
6. Run the app again and notice "Home" and "About" menu items are not properly rendered (styled) and there is one Javascript error in Firebug Console (this.container is undefined).

Any idea what might be going on here? I have tested this in Firefox 7.0.1 and 3.16.13 and same issue.

Turns out this was happening because of outdated 51 Degrees files, updating them fixed it.