diff --git a/grum/mainwin.py b/grum/mainwin.py
index a80e250..c0c1a93 100644
--- a/grum/mainwin.py
+++ b/grum/mainwin.py
@@ -109,7 +109,7 @@ class MainWindow(QMainWindow):
         The configuration is forwarded to the constructor of PlotDescription.
         Allowed keys are: title, xlabel, ylabel, xs, ys.
         """
-        desc = self.add_new_desc_to_list(name, cfg)
+        desc = self.add_new_desc_to_list(PlotDescription, name, cfg)
         if self.menu_settings.checkboxes["Open new plots"].isChecked():
             if not self.mdi.findSubWindow(name):
                 self.sig_make_new_plot.emit(name, desc)
@@ -150,7 +150,7 @@ class MainWindow(QMainWindow):
         The configuration is forwarded to the constructor of ImageDescription.
         Allowed keys are: title, xlabel, ylabel, image.
         """
-        desc = self.add_new_desc_to_list(name, cfg, Desc=ImageDescription) #TODO: clean up Desc argument
+        desc = self.add_new_desc_to_list(ImageDescription, name, cfg)
         if self.menu_settings.checkboxes["Open new plots"].isChecked():
             sub = self.mdi.findSubWindow(name)
             if sub:
@@ -209,8 +209,8 @@ class MainWindow(QMainWindow):
         for fn in fns:
             data = read_dict(fn)
             for k, v in data.items():
-                Desc = ImageDescription if "image" in v else PlotDescription #TODO
-                self.add_new_desc_to_list(k, v, Desc=Desc)
+                DescType = ImageDescription if "image" in v else PlotDescription #TODO
+                self.add_new_desc_to_list(DescType, k, v)
 
 
     def on_file_save(self):
@@ -228,8 +228,8 @@ class MainWindow(QMainWindow):
 
     # Plumbing
 
-    def add_new_desc_to_list(self, name, cfg, Desc=PlotDescription): #TODO
-        desc = Desc(name, **cfg)
+    def add_new_desc_to_list(self, DescType, name, cfg):
+        desc = DescType(name, **cfg)
         self.lst.set(name, desc)
         return desc
 
@@ -255,13 +255,14 @@ class MainWindow(QMainWindow):
         for i in items:
             i.timestamps.access.update()
             i.set_alarm(False)
+        items = (i for i in items if isinstance(i.value, PlotDescription)) #TODO
         descs = {i.key: i.value for i in items}
         names = descs.keys()
         name = " | ".join(names)
         self.activate_or_make_subwin(MDISubMultiPlot, name, descs)
 
 
-    #TODO: the following two could be methods to MDIArea?
+    #TODO: the following two could be methods of MDIArea?
 
     def activate_or_make_subwin(self, MDISubType, name, *args, **kwargs):
         sub = self.mdi.findSubWindow(name)