Adding custom default language hides older content

When changing the default language from English to Custom English old content does not display.

I have a forum. In the localizernode table, for the column called locale, all nodes created with the default Drupal english is set to en. When I create a custom language eg. Custom English, Drupal does not allow me to set its language code as en, so I have to set it to something like en-US or en-UK. This presents a problem if I set the custom language type to default, as all old content will be referenced as en rather than en-US or en-UK. So in my default forum view I see 0 posts and 0 topics.

In my case I don't want to have to English language types, just one customised English.

This may not be a localizer problem, but this situation may be the same for anyone who wishes to change the default english strings that come with Drupal.

Would you suggest running a sql query to update the column in the localizernode table to change all rows with en to en-US for example? Maybe this has already been solved in the dev version. I'll have a look.