Hello!
Sorry for my english ;]
I have the same problem. Version my Roundcube 1.1.4.
In log RoundCube:
PHP Warning: Missing argument 1 for message_label::message_label_imap_set() in /home/tyszek/public_html/poczta/plugins/message_label/message_label.php on line 230
Anyone know how to fix it?