No translation for 'One Response to...'

[remcobronsomanythoughtsnl 0]

In PlatformPro for some reason this line isn't translated by the .mo .po files:

printf( _n( 'One Response to %2$s', '%1$s Responses to %2$s', get_comments_number(), 'pagelines' ),

I resolved this by changing it in the comments.php but it should have been picked-up by the translation files, right? Is there anything in the code or in the .mo and .po files I can change to make this happen?

[cmunns 16]

This may be a WordPress issue for now... http://core.trac.wordpress.org/ticket/13651