Hi Julian.

 I tried to find out the same thing, but had no luck(ref http://www.episerverworld.com/Forum/Pages/thread.aspx?id=16030). One "work around" is for the user to go the Portuguese url for the site first, then enter edit mode. Then the current threads culture will be set to Portuguese. With Reflector i found out that the page tree language drop down is set with EPiServer.Globalization.ContentLanguage.PreferredCulture.Name, and this is determined by the threads current culture.

Let me know if you find out a way to solve this matter!

 BR,

Tore 

I've had a hunt and agree with Tore - it seems that the whole Edit context picks up your culture. As far as I can tell you'd need to 'set your culture' before you even enter the Edit side.

One way you could achieve this is by detecting client browser locale on your start page and auto-directing to the appropriate language branch (if available). That would mean the user would already have set their culture before they tried to log in. This might not be a bad idea anyway but depending on your end user base it might not be ideal.

Another way might be to abstract the virtual folder for your UI as a VPP and then do some clever jiggery pokery to set the culture before the actual Edit page was invoked. You could use a custom VPP, for example. 

You could go for a techie solution such as a HTTP module to try and switch culture on the fly on certain requests but there's all sorts of issues with that and I think it would be a sledgehammer to crack a nut, so to speak!

Let me know if you find a cleaner solution that these - I might be looking too hard for a solution to a non-existent problem!

- Dan