Hello,
there is a bug in google calendar.
Html entities appears on it with special character ( é à è )
To avoid this, add after line 171 : $Description = requestToXML($aRequest['description'], ENT_COMPAT, 'UTF-8');
This line : $Description = html_entity_decode($Description);
Add the same on message_raid_update.php after line 92
Don't know if this is a security issue but it fix the problem.