Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIAddDiskEncryptionPasswordDialog.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIAddDiskEncryptionPasswordDialog.cpp	(revision 54934)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIAddDiskEncryptionPasswordDialog.cpp	(revision 54935)
@@ -411,4 +411,7 @@
 void UIAddDiskEncryptionPasswordDialog::prepare()
 {
+    /* Configure self: */
+    setWindowModality(Qt::WindowModal);
+
     /* Create main-layout: */
     QVBoxLayout *pMainLayout = new QVBoxLayout(this);
Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineLogic.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineLogic.cpp	(revision 54934)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/UIMachineLogic.cpp	(revision 54935)
@@ -2437,6 +2437,7 @@
     {
         /* Create corresponding dialog: */
+        QWidget *pDlgParent = windowManager().realParentWindow(activeMachineWindow());
         QPointer<UIAddDiskEncryptionPasswordDialog> pDlg =
-             new UIAddDiskEncryptionPasswordDialog(activeMachineWindow(),
+             new UIAddDiskEncryptionPasswordDialog(pDlgParent,
                                                    machineName(),
                                                    encryptedMediums);