Error when change panel from component editing. ZK error: "Only one child is allowed: <Center...>"

How to reproduce:
1) click to "Components" in left side
2) with single click select any component
3) press to "Настроить" - new window opens
4) click to any item (Components, Topic Types, etc.) in left side

Comment:
Maybe it appears because new opened window (with caption "Редактирование компонента") opens in full width mode. Maybe we need that it will be opened in modal mode, that prevents clicking on items in left menu.

Related to:
http://jira.jtalks.org/browse/POULPE-108
http://jira.jtalks.org/browse/POULPE-116
http://jira.jtalks.org/browse/POULPE-115