Patch from Michał Mirosław.
---- a/program/include/rcube_message.php.orig 2012-01-17 08:50:40.000000000 +0100
-+++ a/program/include/rcube_message.php 2012-09-06 19:54:54.000000000 +0200
+Index: roundcube/program/include/rcube_message.php
+===================================================================
+--- roundcube.orig/program/include/rcube_message.php 2012-09-29 11:30:54.555045159 +0200
++++ roundcube/program/include/rcube_message.php 2012-09-29 11:31:51.044174849 +0200
@@ -622,8 +622,7 @@
$part->body = $this->imap->get_message_part($this->uid, $part->mime_id, $part);