Adding new translation to content without publishing it right away will result in edit view always opening in the main translation regardless language of the version selected.

Steps to reproduce
1. Clean installation of eZ Platform 2.4/2.5
2. Add new language: Polish, pol-PL
3. In the content tree root create a new Folder in English, name it Folder Eng. Publish it.
4. When viewing newly created Folder Eng go to Translations tab and add new Translation (Polish). In polish translation name folder Folder Pol. Press Save button.
5. After being returned to Folder Eng content view, press Edit on right sidebar. From Available versions, choose Polish Version.
OR
5. Go to Versions tab in Folder Eng content view, click edit button next to Polish version.

Result
There will be a Polish version opened for editing (version no) but in English language and with English language values.