Hi Gilby.
First of all : GREAT WORK !
BUT
Your mime.php seems not to handle the following mime format:
=?iso-8859-1?q?this=20is=20some=20text?=
Many usernames contain special charsets that seem to to be encoded this way.
Where is your mime.php from ? Is there a newer version with support for it ?
PS: More Info about the format:
http://www.faqs.org/rfcs/rfc2047.html
Thank You
etom