I've posted a ticket for the page builder, I've seen many times those problems reported but never got fixed.. (lacking delete button for pages, activate/deactivate page button, reset page to default button, inaccurate slider for columns and page width)
TICKET: http://www.boonex.com/trac/dolphin/ticket/1647
http://www.boonex.com/trac/dolphin/ticket/1592