fMailbox regular IMAP vs Exchange 2007 style IMAP

Hello there,

i am using fMailbox to query a mailbox for e-mail (duh!), which i then parse and put in a database. When i query a Mailbox that sits on a regular MDAEMON (Windoze) or Dovecot (BSD) Server, things work pretty good. The trouble is in the end this program will have to query an Exchange 2007 IMAP Mailbox, and while it connects just fine, it will always report that there are no messages, even though there clearly are. What gives, any Idea? Using pop3 instead of imap works good as well btw.

PHP-IMAP used to work okay with the Exchange Server IMAP Mailbox, but obviously it has some other shortcomings which led me to fMailbox.

$connection = new fMailbox('imap', '192.168.7.100', 'testmailbox', 'Password1234',NULL,TRUE,10);
$emails = $connection->listMessages();
// When 192.168.7.100 is an Exchange 2007 Server providing IMAP,
// $emails will be empty no matter what while
// pop3 works as expected though

Thanks for any hints or support...