diff --git a/src/gui/components/cc_frm_signalbars.cpp b/src/gui/components/cc_frm_signalbars.cpp
index 703c5e67c..4dc677e93 100644
--- a/src/gui/components/cc_frm_signalbars.cpp
+++ b/src/gui/components/cc_frm_signalbars.cpp
@@ -192,7 +192,9 @@ void CSignalBar::initSBarName()
 void CSignalBar::Refresh()
 {
 	//get current value from frontend
-	sb_signal = sb_frontend->getSignalStrength();
+	sb_signal = 0;
+	if (sb_frontend)
+		sb_signal = sb_frontend->getSignalStrength();
 
 	//reinit items with current values
 	initSBItems();
@@ -242,7 +244,9 @@ void CSignalBar::paint(bool do_save_bg)
 void CSignalNoiseRatioBar::Refresh()
 {
 	//get current value from frontend
-	sb_signal = sb_frontend->getSignalNoiseRatio();
+	sb_signal = 0;
+	if (sb_frontend)
+		sb_signal = sb_frontend->getSignalNoiseRatio();
 
 	//reinit items with current values
 	initSBItems();
@@ -338,10 +342,8 @@ void CSignalBox::paintScale()
 void CSignalBox::paint(bool do_save_bg)
 {
 	//paint frame and body
-	if (!is_painted){
-		initSignalItems();
+	if (!is_painted)
 		paintForm(do_save_bg);
-	}
 
 	//paint current signal value
 	paintScale();
diff --git a/src/gui/components/cc_frm_signalbars.h b/src/gui/components/cc_frm_signalbars.h
index 110060b66..b69516a6c 100644
--- a/src/gui/components/cc_frm_signalbars.h
+++ b/src/gui/components/cc_frm_signalbars.h
@@ -116,7 +116,7 @@ class CSignalBar : public CComponentsForm, public CCTextScreen
 		CSignalBar(const int& xpos, const int& ypos, const int& w, const int& h, CFrontend *frontend_ref, const std::string& sb_name = "SIG", CComponentsForm *parent = NULL);
 
 		///assigns the current used frontend, simplified a tuner object, see frontend_c.h
-		virtual void setFrontEnd(CFrontend *frontend_ref){sb_frontend = frontend_ref;};
+		virtual void setFrontEnd(CFrontend *frontend_ref){if (sb_frontend != frontend_ref) {sb_lastsig = 0; sb_frontend = frontend_ref;}}
 		///assigns font for caption
 		virtual void setTextFont(Font* font_text){sb_font = font_text;};
 		///sets the caption color, see also property 'sb_caption_color'
@@ -298,6 +298,9 @@ class CSignalBox : public CComponentsForm, public CCTextScreen
 		///returns the signal noise ratio object, type = CSignalNoiseRatioBar*
 		CSignalNoiseRatioBar* getLabelObject(){return snrbar;};
 
+		///assigns the current used frontend, simplified a tuner object, see frontend_c.h
+		void setFrontEnd(CFrontend *frontend_ref){sbx_frontend = frontend_ref;}
+
 		///sets the caption color of signalbars, see also property 'sbx_caption_color'
 		void setTextColor(const fb_pixel_t& caption_color){ sbx_caption_color = caption_color;};
 		///get caption color of signalbars, see also property 'sbx_caption_color'