[Plugin: SEO SearchTerms Tagging 2] Aprostrophe becoming Backslash

I think you have to replace :
$query = str_replace("'", '', $query);
with :
$query = str_replace("'", '’', $query); // must be a real quote made with RTF file !
or :
$query = str_replace("'", '"', $query);
in :
function pk_stt2_function_get_terms($d)
But I’m not sure, because there are not a lot of people to tell something about it… It’s possible that our websites are misconfigured.