If that's the module's title as set in the manager, then that's expected behavior. Same concept for frontend modules applies to the admin too; the title is user input and isn't translated.

In previous versions it was translated, and in this version there are translation files for it, in en-GB admin files... the only thing missing is the jtext string....

Nope, in previous version they were not "Translatable" except changing manually the Titles as they are admin Modules like Michael said.
Go to: Extensions -> Modules
then filter 'Administrator'

ok thanks for your time guys, i see what u mean... have a nice day :D

Closing as issue is solved :)

In fact, we DID have this feature in 2.5, but not with this string.
It was:

MOD_LOGGED_TITLE="Last Logged-in Users"
MOD_LOGGED_TITLE_1="Last Logged-in User"
MOD_LOGGED_TITLE_MORE="Last %s Logged-in Users"

Code used:

    public static function getTitle($params)
    {
        return JText::plural('MOD_LOGGED_TITLE', $params->get('count'));
    }

result:

For a reason that ignore, this was changed in 3.x...

Oh thank u :D Any chance they could revise this?!

On it.

Thank u so much for your time.... have a nice day :D

Please test #7925

Thank u so much infograf768, you are a life savior... working like a charm... One last question is this now part of joomla installation or only your branch?! im new at programming and github...

If the PR gets tested and PLT decides to implement it, it will be part of Joomla. But earliest at 3.5 since it's a new feature.

ok thx guys... thx for your work... Im hopping to learn more and more about joomla development...