Comment 1 for bug 514251

Just to shedding light on translations: when lang=False, you get en_EN because for the moment it's hardcoded. If I understand Fabien right, this is by design.
He commented on bug #400256 :
"I invalidate this bug. It's important for us to have a clean approach on being fully multi-languages. Everything must be in english and the server send translated versions to the client.

It's the same for dates, floats, ... Example: dates are stored in SQL format but the format is adapted at the client side depending on the user. For sentences, everything in the base module and fields are in english and the client send/receive translations according to the user."
Your solution is only good if that's what happens in other places (we need to keep thing coherent). If it's not, then please file a Blueprint, I'll support it as much as I can.
I hope this helps.
Lionel.