diff --git a/src/DockAreaTabBar.cpp b/src/DockAreaTabBar.cpp
index 1b26435..48e3c22 100644
--- a/src/DockAreaTabBar.cpp
+++ b/src/DockAreaTabBar.cpp
@@ -36,6 +36,7 @@
 #include <QBoxLayout>
 #include <QApplication>
 #include <QtGlobal>
+#include <QTimer>
 
 #include "FloatingDockContainer.h"
 #include "DockAreaWidget.h"
@@ -107,7 +108,12 @@ void DockAreaTabBarPrivate::updateTabs()
 		{
 			TabWidget->show();
 			TabWidget->setActiveTab(true);
-			_this->ensureWidgetVisible(TabWidget);
+			// Sometimes the synchronous calculation of the rectangular area fails
+			// Therefore we use QTimer::singleShot here to execute the call
+			// within the event loop - see #520
+			QTimer::singleShot(0, [&, TabWidget]{
+			    _this->ensureWidgetVisible(TabWidget);
+			});
 		}
 		else
 		{
diff --git a/src/DockAreaWidget.cpp b/src/DockAreaWidget.cpp
index d44115e..c1d8d55 100644
--- a/src/DockAreaWidget.cpp
+++ b/src/DockAreaWidget.cpp
@@ -140,6 +140,7 @@ public:
 			{
 				LayoutItem->widget()->setParent(nullptr);
 			}
+			delete LayoutItem;
 			m_CurrentWidget = nullptr;
 			m_CurrentIndex = -1;
 		}
diff --git a/src/FloatingDockContainer.cpp b/src/FloatingDockContainer.cpp
index 0a2cdc7..927910d 100644
--- a/src/FloatingDockContainer.cpp
+++ b/src/FloatingDockContainer.cpp
@@ -1133,6 +1133,11 @@ void CFloatingDockContainer::hideAndDeleteLater()
 	d->AutoHideChildren = false;
 	hide();
 	deleteLater();
+	if (d->DockManager)
+	{
+		d->DockManager->removeFloatingWidget(this);
+		d->DockManager->removeDockContainer(this->dockContainer());
+	}
 }
 
 //============================================================================