Index: /trunk/src/VBox/Frontends/VirtualBox/src/medium/UIMediumManager.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/medium/UIMediumManager.cpp	(revision 58855)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/medium/UIMediumManager.cpp	(revision 58856)
@@ -1231,9 +1231,21 @@
         pTreeWidget->sortItems(0, Qt::AscendingOrder);
         if (iColumns > 0)
+#if QT_VERSION >= 0x050000
+            pTreeWidget->header()->setSectionResizeMode(0, QHeaderView::Fixed);
+#else /* QT_VERSION < 0x050000 */
             pTreeWidget->header()->setResizeMode(0, QHeaderView::Fixed);
+#endif /* QT_VERSION < 0x050000 */
         if (iColumns > 1)
+#if QT_VERSION >= 0x050000
+            pTreeWidget->header()->setSectionResizeMode(1, QHeaderView::ResizeToContents);
+#else /* QT_VERSION < 0x050000 */
             pTreeWidget->header()->setResizeMode(1, QHeaderView::ResizeToContents);
+#endif /* QT_VERSION < 0x050000 */
         if (iColumns > 2)
+#if QT_VERSION >= 0x050000
+            pTreeWidget->header()->setSectionResizeMode(2, QHeaderView::ResizeToContents);
+#else /* QT_VERSION < 0x050000 */
             pTreeWidget->header()->setResizeMode(2, QHeaderView::ResizeToContents);
+#endif /* QT_VERSION < 0x050000 */
         pTreeWidget->header()->setStretchLastSection(false);
         pTreeWidget->setSortingEnabled(true);
Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIAddDiskEncryptionPasswordDialog.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIAddDiskEncryptionPasswordDialog.cpp	(revision 58855)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIAddDiskEncryptionPasswordDialog.cpp	(revision 58856)
@@ -424,6 +424,11 @@
     verticalHeader()->setDefaultSectionSize((int)(verticalHeader()->minimumSectionSize() * 1.33));
     horizontalHeader()->setStretchLastSection(false);
+#if QT_VERSION >= 0x050000
+    horizontalHeader()->setSectionResizeMode(UIEncryptionDataTableSection_Id, QHeaderView::Interactive);
+    horizontalHeader()->setSectionResizeMode(UIEncryptionDataTableSection_Password, QHeaderView::Stretch);
+#else /* QT_VERSION < 0x050000 */
     horizontalHeader()->setResizeMode(UIEncryptionDataTableSection_Id, QHeaderView::Interactive);
     horizontalHeader()->setResizeMode(UIEncryptionDataTableSection_Password, QHeaderView::Stretch);
+#endif /* QT_VERSION < 0x050000 */
 }
 
Index: /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsExtension.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsExtension.cpp	(revision 58855)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsExtension.cpp	(revision 58856)
@@ -97,7 +97,13 @@
     //m_pPackagesTree->header()->hide();
     m_pPackagesTree->header()->setStretchLastSection(false);
+#if QT_VERSION >= 0x050000
+    m_pPackagesTree->header()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
+    m_pPackagesTree->header()->setSectionResizeMode(1, QHeaderView::Stretch);
+    m_pPackagesTree->header()->setSectionResizeMode(2, QHeaderView::ResizeToContents);
+#else /* QT_VERSION < 0x050000 */
     m_pPackagesTree->header()->setResizeMode(0, QHeaderView::ResizeToContents);
     m_pPackagesTree->header()->setResizeMode(1, QHeaderView::Stretch);
     m_pPackagesTree->header()->setResizeMode(2, QHeaderView::ResizeToContents);
+#endif /* QT_VERSION < 0x050000 */
     m_pPackagesTree->setContextMenuPolicy(Qt::CustomContextMenu);
     connect(m_pPackagesTree, SIGNAL(currentItemChanged(QTreeWidgetItem*, QTreeWidgetItem*)),
Index: /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsInput.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsInput.cpp	(revision 58855)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsInput.cpp	(revision 58856)
@@ -571,6 +571,11 @@
     verticalHeader()->setDefaultSectionSize((int)(verticalHeader()->minimumSectionSize() * 1.33));
     horizontalHeader()->setStretchLastSection(false);
+#if QT_VERSION >= 0x050000
+    horizontalHeader()->setSectionResizeMode(UIHotKeyTableSection_Name, QHeaderView::Interactive);
+    horizontalHeader()->setSectionResizeMode(UIHotKeyTableSection_Value, QHeaderView::Stretch);
+#else /* QT_VERSION < 0x050000 */
     horizontalHeader()->setResizeMode(UIHotKeyTableSection_Name, QHeaderView::Interactive);
     horizontalHeader()->setResizeMode(UIHotKeyTableSection_Value, QHeaderView::Stretch);
+#endif /* QT_VERSION < 0x050000 */
 
     /* Reinstall delegate: */
Index: /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsNetwork.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsNetwork.cpp	(revision 58855)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/settings/global/UIGlobalSettingsNetwork.cpp	(revision 58856)
@@ -389,6 +389,11 @@
         m_pTreeNetworkNAT->setColumnCount(2);
         m_pTreeNetworkNAT->header()->setStretchLastSection(false);
+#if QT_VERSION >= 0x050000
+        m_pTreeNetworkNAT->header()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
+        m_pTreeNetworkNAT->header()->setSectionResizeMode(1, QHeaderView::Stretch);
+#else /* QT_VERSION < 0x050000 */
         m_pTreeNetworkNAT->header()->setResizeMode(0, QHeaderView::ResizeToContents);
         m_pTreeNetworkNAT->header()->setResizeMode(1, QHeaderView::Stretch);
+#endif /* QT_VERSION < 0x050000 */
         m_pTreeNetworkNAT->setContextMenuPolicy(Qt::CustomContextMenu);
         connect(m_pTreeNetworkNAT, SIGNAL(currentItemChanged(QTreeWidgetItem*, QTreeWidgetItem*)),
Index: /trunk/src/VBox/Frontends/VirtualBox/src/widgets/UIApplianceEditorWidget.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/widgets/UIApplianceEditorWidget.cpp	(revision 58855)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/widgets/UIApplianceEditorWidget.cpp	(revision 58856)
@@ -1127,5 +1127,9 @@
     m_pTvSettings->setAllColumnsShowFocus(true);
     m_pTvSettings->header()->setStretchLastSection(true);
+#if QT_VERSION >= 0x050000
+    m_pTvSettings->header()->setSectionResizeMode(QHeaderView::ResizeToContents);
+#else /* QT_VERSION < 0x050000 */
     m_pTvSettings->header()->setResizeMode(QHeaderView::ResizeToContents);
+#endif /* QT_VERSION < 0x050000 */
 
     /* Hidden by default */