QtitanDocking2.3.0+QtitanRibbon5.0.0 content of document panel not shown

I use QtitanRibbon 5.0.0beta2 and QtitanDocking 2.3.0.
I added two DocumentPanel. When i click on the tab of the documents nothing happens. Always the content of panel 2 is shown. But i cannot switch between panel 1 and 2.

Here is the code:
#include <QtitanRibbon.h>
#include <QtitanDocking.h>

GuiTest::GuiTest(QWidget *parent)
: RibbonMainWindow(parent)
{
QLatin1String m_defaultStyle("windowsvista");
qApp->style()->setObjectName(m_defaultStyle);

ui.setupUi(this);

setWindowTitle("QtitanRibbon + QtitanDocking");

ribbonBar()->setFrameThemeEnabled(true);
ribbonBar()->setTitleBarVisible(true);

QWidget *widget = new QWidget;
DockPanelManager *dockPanelManager = new DockPanelManager(widget);
dockPanelManager->setDockPanelTransparentWhileDragging(true);
dockPanelManager->setArrowMarkersShown(true);
dockPanelManager->setDockPanelFullContentsWhileDraggingShown(true);
setCentralWidget(widget);

dockPanelManager->centralLayoutPanel();

////// 2 - Creating a ribbon
ribbonBar()->setFrameThemeEnabled();
ribbonBar()->addPage("&Buttons1");

////// 3 - Creating a dockBarManager
DockBarManager* managerBar = new DockBarManager(widget);
DockToolBar* tooBar = managerBar->addToolBar("My Toolbar", Qtitan::DockBarTop);
tooBar->addAction("Button");

////// 4 - Creating a panelManager
DockWidgetPanel* dockPanel1 = dockPanelManager->addDocumentPanel("My Panel_1");
dockPanel1->setWidget(new QLabel("panel1"));
DockWidgetPanel* dockPanel2 = dockPanelManager->addDocumentPanel("My Panel_2");
dockPanel2->setWidget(new QLabel("panel2"));
}

Please find a bug-fix in your email box. The bugfix will be available in the next update. We are sorry for this inconvenience.