Index: trunk/BNC/src/bncwindow.cpp
===================================================================
--- trunk/BNC/src/bncwindow.cpp	(revision 5082)
+++ trunk/BNC/src/bncwindow.cpp	(revision 5083)
@@ -82,4 +82,7 @@
 
 #ifdef GNSSCENTER_PLUGIN
+  if (BNC_CORE != 0) {
+    QMessageBox::critical(this, "Caution", "Only one BNC allowed");
+  }
   BNC_CORE = new t_bncCore(true);
   BNC_CORE->setConfFileName("");
@@ -2042,4 +2045,9 @@
   }
 
+#ifdef GNSSCENTER_PLUGIN
+  delete BNC_CORE;
+  BNC_CORE = 0;
+#endif
+
   QMainWindow::closeEvent(event);
 }