They need to to meet CO2 emmision standards. If the average CO2 emmision of all the models is below this standard they don't need to modify the cool models.

This way I can reproduce the problem: Using FireFox 2.0.0.11 - Open CodeProject.com - Log in if needed If I close and reopen my browser I'm still logged in. - Now I select 'C#' from the green bar Now when I close and reopen my browser I'm not logged in.