I'm not sure if it's actually a bug, but in 0.8 version tab's labels for Search and Recent tabs are not translated even if the proper lang file exists in proper place.
As far as I can see it's because the wrong texdomain stated in box.php (line 64 and line 72).
Could you please fix it for future releases.
In case it may be usefull - I've made the quick translation of this plugin into Russian. Files (in case you'd like to include them into packag) could be found here http://cl.ly/8re4
Thanks a lot for your great work with this plugin.