'Tree view' resets when opening a file

BackGround:

This appears new with the 3.1.x release.
1. Select a repository from the 'Repositories' tab.
2. Navigate using the 'tree view' on the left hand side (expand it if required).
3. Drill down into a sub-directory (expanding the tree).
4. Select a file to open it on the right.
The tree view is then reset - i.e. any opened folders are closed again, which is confusing to the user.