Hi I like this plugin 🙂
Plugin Code is very clear and easy to make some custom hacks (multilingual…)

I spend a more than 30 minutes to get rid of the message that says :

Recipient “ID” and “Name” doesn’t match. Cheating huh?

I wasn’t cheating 🙂

Finally I found that the current version don’t take care about WordPress usernames where we find a Capital letters 😉

So we have to replace :
if($name != $to)
by
if(strtolower($name) != strtolower($to))

And taht’s it 😉