Go and check the configurations values only when needed.

modules/gui/qt4/components/open_panels.cpp

@@ -644,7 +644,6 @@ CaptureOpenPanel::CaptureOpenPanel( QWidget *_parent, intf_thread_t *_p_intf ) :
     bdaPropLayout->addWidget( bdaBandLabel, 2, 0 );
 
     bdaBandBox = new QComboBox;
-    setfillVLCConfigCombo( "dvb-bandwidth", p_intf, bdaBandBox );
     bdaPropLayout->addWidget( bdaBandBox, 2, 1 );
 
     bdaBandLabel->hide();
@@ -689,7 +688,6 @@ CaptureOpenPanel::CaptureOpenPanel( QWidget *_parent, intf_thread_t *_p_intf ) :
     v4l2PropLayout->addWidget( v4l2StdLabel, 0 , 0 );
 
     v4l2StdBox = new QComboBox;
-    setfillVLCConfigCombo( "v4l2-standard", p_intf, v4l2StdBox );
     v4l2PropLayout->addWidget( v4l2StdBox, 0 , 1 );
     v4l2PropLayout->addItem( new QSpacerItem( 20, 20, QSizePolicy::Expanding ),
             1, 0, 3, 1 );
@@ -724,7 +722,6 @@ CaptureOpenPanel::CaptureOpenPanel( QWidget *_parent, intf_thread_t *_p_intf ) :
     v4lPropLayout->addWidget( v4lNormLabel, 0 , 0 );
 
     v4lNormBox = new QComboBox;
-    setfillVLCConfigCombo( "v4l-norm", p_intf, v4lNormBox );
     v4lPropLayout->addWidget( v4lNormBox, 0 , 1 );
 
     QLabel *v4lFreqLabel = new QLabel( qtr( "Frequency" ) );
@@ -823,7 +820,6 @@ CaptureOpenPanel::CaptureOpenPanel( QWidget *_parent, intf_thread_t *_p_intf ) :
     pvrPropLayout->addWidget( pvrNormLabel, 0, 0 );
 
     pvrNormBox = new QComboBox;
-    setfillVLCConfigCombo( "pvr-norm", p_intf, pvrNormBox );
     pvrPropLayout->addWidget( pvrNormBox, 0, 1 );
 
     QLabel *pvrFreqLabel = new QLabel( qtr( "Frequency" ) );
@@ -1063,23 +1059,35 @@ void CaptureOpenPanel::updateButtons()
         }
         break;
     case DSHOW_DEVICE:
-        /* dshow Main */
-        int line = 0;
-        module_config_t *p_config =
-            config_FindConfig( VLC_OBJECT(p_intf), "dshow-vdev" );
-        vdevDshowW = new StringListConfigControl(
-                VLC_OBJECT(p_intf), p_config, this, false, devLayout, line );
-        line++;
-
-        p_config = config_FindConfig( VLC_OBJECT(p_intf), "dshow-adev" );
-        adevDshowW = new StringListConfigControl(
-                VLC_OBJECT(p_intf), p_config, this, false, devLayout, line );
-        line++;
-        break;
+        {
+            /* dshow Main */
+            int line = 0;
+            module_config_t *p_config =
+                config_FindConfig( VLC_OBJECT(p_intf), "dshow-vdev" );
+            vdevDshowW = new StringListConfigControl(
+                   VLC_OBJECT(p_intf), p_config, this, false, devLayout, line );
+            line++;
+
+            p_config = config_FindConfig( VLC_OBJECT(p_intf), "dshow-adev" );
+            adevDshowW = new StringListConfigControl(
+                   VLC_OBJECT(p_intf), p_config, this, false, devLayout, line );
+            line++;
+        }
+        bvreak;
 #else
     case DVB_DEVICE:
         if( dvbs->isChecked() ) dvbFreq->setSuffix(" kHz");
         if( dvbc->isChecked() || dvbt->isChecked() ) dvbFreq->setSuffix(" Hz");
+        setfillVLCConfigCombo( "dvb-bandwidth", p_intf, bdaBandBox );
+        break;
+    case PVR_DEVICE:
+        setfillVLCConfigCombo( "pvr-norm", p_intf, pvrNormBox );
+        break;
+    case V4L_DEVICE:
+        setfillVLCConfigCombo( "v4l-norm", p_intf, v4lNormBox );
+        break;
+    case V4L2_DEVICE:
+        setfillVLCConfigCombo( "v4l2-standard", p_intf, v4l2StdBox );
         break;
 #endif
     case SCREEN_DEVICE: