Index: /trunk/src/VBox/Frontends/VirtualBox/src/medium/UIMediumDetailsWidget.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/medium/UIMediumDetailsWidget.cpp	(revision 68324)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/medium/UIMediumDetailsWidget.cpp	(revision 68325)
@@ -410,4 +410,11 @@
                 /* Configure layout: */
                 pLayoutSize->setContentsMargins(0, 0, 0, 0);
+#ifdef VBOX_WS_MAC
+                // WORKAROUND:
+                // Using adjusted vertical stretch because there is special widget
+                // which requires more care and attention, UIMediumSizeEditor.
+                pLayoutSize->setRowStretch(0, 3);
+                pLayoutSize->setRowStretch(1, 2);
+#endif
 
                 /* Create size editor: */