Primary/Secondary links : Menu settings is reset to default when editing a translated page

The conditions:
- Multilingual primary menu with 3 languages:
Primary links (en), Primary links (fr), Primary links (el)

- At least one page for each language in the primary menu

- in admin/build/menu/settings,
Default menu for content: set to "Primary links (en)"
(note: this is not a multilingual variable)

When editing a page in (fr) or (el) language, the menu settings is systematically reset to the default value: the page migrates to the menu of the default language.
This can be prevented by resetting the menu before saving the page.

Note : same behaviour for Secondary links of course