There is a problem with the traduction of "writen_by" in the content front of k2 component. I solve this chaging the function on com_k2/helpers/utilities.php from something like:

function writtenBy($gender){
if (is_null($gender))
return JText::_('Written by female');
if ($gender=='m')
return JText::_('Written by male');
if ($gender=='f')
return JText::_('Written by');
}

to:

function writtenBy($gender){
if (is_null($gender))
return JText::_('Written_by');
if ($gender=='m')
return JText::_('Written_male');
if ($gender=='f')
return JText::_('Written_female');
}

And change the same on the respect language traduction files. Please fix it on the original files of this great component

Thanks dude. Haven't tried this yet. But will do as it is a bit of a pain.