diff --git a/src/frontends/Selection.h b/src/frontends/Selection.h
index ac902ffc1e..fb835e7ffb 100644
--- a/src/frontends/Selection.h
+++ b/src/frontends/Selection.h
@@ -62,7 +62,7 @@ public:
 	 * This does always return true on systems that don't have a real
 	 * selection.
 	 */
-	virtual bool empty() const = 0;
+	virtual bool empty() = 0;
 };
 
 } // namespace frontend
diff --git a/src/frontends/qt4/GuiSelection.cpp b/src/frontends/qt4/GuiSelection.cpp
index f483a3b1b2..0f6fb88ac5 100644
--- a/src/frontends/qt4/GuiSelection.cpp
+++ b/src/frontends/qt4/GuiSelection.cpp
@@ -91,19 +91,21 @@ void GuiSelection::put(docstring const & str)
 
 void GuiSelection::on_dataChanged()
 {
-	text_selection_empty_ = qApp->clipboard()->
-		text(QClipboard::Selection).isEmpty();
-	LYXERR(Debug::SELECTION, "GuiSelection::on_dataChanged::filled: " << !text_selection_empty_);
+	schedule_check_ = true;
+	LYXERR(Debug::SELECTION, "GuiSelection::on_dataChanged");
 }
 
 
-bool GuiSelection::empty() const
+bool GuiSelection::empty()
 {
 	if (!selection_supported_)
 		return true;
 
-	LYXERR(Debug::SELECTION, "GuiSelection::filled: " << !text_selection_empty_);
+	if (schedule_check_)
+		text_selection_empty_ = qApp->clipboard()->
+			text(QClipboard::Selection).isEmpty();
 
+	LYXERR(Debug::SELECTION, "GuiSelection::filled: " << !text_selection_empty_);
 	return text_selection_empty_;
 }
 
diff --git a/src/frontends/qt4/GuiSelection.h b/src/frontends/qt4/GuiSelection.h
index c7f2096aa8..f76dc2642c 100644
--- a/src/frontends/qt4/GuiSelection.h
+++ b/src/frontends/qt4/GuiSelection.h
@@ -37,14 +37,24 @@ public:
 	void haveSelection(bool own);
 	docstring const get() const;
 	void put(docstring const & str);
-	bool empty() const;
+	bool empty();
 	//@}
 
 private Q_SLOTS:
 	void on_dataChanged();
 
 private:
+	// Cache which is to speed up selection-status read
+	// (4 calls when openi Edit menu).
 	bool text_selection_empty_;
+	// Direct call clipboard()->text(QClipboard::Selection) inside onDataChanged causes
+	// selection to be obtained. Now imagine the some LyX instance A, when making selection -
+	// each change triggers onDataChange in all others instances for each mouse
+	// or keyboard move. This in turn causes many calls of requestSelection in A
+	// which interferes with the selecting itself. As a result middle button pasting
+	// for more instances don't work and debugging is a hell. So we just schedule
+	// obtaining of selection on the time empty() is actually called.
+	bool schedule_check_;
 	bool const selection_supported_;
 };