Last replied not translated on the site though translation exists in the language file

Hello,
I encounter a bug. Indeed I have translated all the french side site sentences and one that is translated is not replaced. I wonder if this is not hard coded somewhere.

The sentense is "Last replied by"

Could you help please ?

here is the screen capture.

By the way, when do you plan an update of version 2.0C ?

Regards

Kris