Is it possible to translate some strings, but not all, in a separate resource file without Lint complaining about MissingTranslation?
For example: m
If you are using Eclipse, please look at the toolbar buttons of the Lint warnings view. One of them is called "Ignore in file". This should help, but only if Lint assigns the error to your "US" file. That button simply modifies the lint.xml file in your project, so you can investigate (and undo) that easily.
More details about that file specific suppression are at http://tools.android.com/tips/lint/suppressing-lint-warnings