diff --git a/apps/modes_rx b/apps/modes_rx
index ebc4cf0..29c9fc9 100755
--- a/apps/modes_rx
+++ b/apps/modes_rx
@@ -107,8 +107,7 @@ def main():
     #updates.append(sbs1port.add_pending_conns)
 
   tb.run()
-  tb._pubsub.done.set()
-  tb._pubsub.finished.wait(0.2)
+  tb.cleanup()
 
   if printer is not None:
     printer.done.set()
@@ -117,6 +116,5 @@ def main():
     sqldb.done = True
     #sqldb.join()
 
-
 if __name__ == '__main__':
   main()
diff --git a/python/radio.py b/python/radio.py
index e366a89..d3b1655 100644
--- a/python/radio.py
+++ b/python/radio.py
@@ -198,3 +198,7 @@ class modes_radio (gr.top_block):
         
 
     print "Rate is %i" % (options.rate,)
+
+  def cleanup(self):
+    self._pubsub.done.set()
+    self._pubsub.finished.wait(0.2)
diff --git a/python/sql.py b/python/sql.py
index 9088378..02dff5a 100644
--- a/python/sql.py
+++ b/python/sql.py
@@ -115,8 +115,6 @@ class output_sql(air_modes.parse, threading.Thread):
     data = air_modes.modes_reply(long(data, 16))
     ecc = long(ecc, 16)
 #   reference = float(reference)
-
-
     query = None
     msgtype = data["df"]
     if msgtype == 17:
@@ -128,36 +126,29 @@ class output_sql(air_modes.parse, threading.Thread):
     icao24 = data["aa"]
     bdsreg = data["me"].get_type()
 
-    retstr = None
-
     if bdsreg == 0x08:
       (msg, typename) = self.parseBDS08(data)
-      retstr = "INSERT OR REPLACE INTO ident (icao, ident) VALUES (" + "%i" % icao24 + ", '" + msg + "')"
-
+      return "INSERT OR REPLACE INTO ident (icao, ident) VALUES (" + "%i" % icao24 + ", '" + msg + "')"
     elif bdsreg == 0x06:
       [ground_track, decoded_lat, decoded_lon, rnge, bearing] = self.parseBDS06(data)
       altitude = 0
       if decoded_lat is None: #no unambiguously valid position available
-        retstr = None
+        raise CPRNoPositionError
       else:
-        retstr = "INSERT INTO positions (icao, seen, alt, lat, lon) VALUES (" + "%i" % icao24 + ", datetime('now'), " + str(altitude) + ", " + "%.6f" % decoded_lat + ", " + "%.6f" % decoded_lon + ")"
-
+        return "INSERT INTO positions (icao, seen, alt, lat, lon) VALUES (" + "%i" % icao24 + ", datetime('now'), " + str(altitude) + ", " + "%.6f" % decoded_lat + ", " + "%.6f" % decoded_lon + ")"
     elif bdsreg == 0x05:
       [altitude, decoded_lat, decoded_lon, rnge, bearing] = self.parseBDS05(data)
       if decoded_lat is None: #no unambiguously valid position available
-        retstr = None
+        raise CPRNoPositionError
       else:
-        retstr = "INSERT INTO positions (icao, seen, alt, lat, lon) VALUES (" + "%i" % icao24 + ", datetime('now'), " + str(altitude) + ", " + "%.6f" % decoded_lat + ", " + "%.6f" % decoded_lon + ")"
-
+        return "INSERT INTO positions (icao, seen, alt, lat, lon) VALUES (" + "%i" % icao24 + ", datetime('now'), " + str(altitude) + ", " + "%.6f" % decoded_lat + ", " + "%.6f" % decoded_lon + ")"
     elif bdsreg == 0x09:
       subtype = data["bds09"].get_type()
       if subtype == 0:
         [velocity, heading, vert_spd, turnrate] = self.parseBDS09_0(data)
-        retstr = "INSERT INTO vectors (icao, seen, speed, heading, vertical) VALUES (" + "%i" % icao24 + ", datetime('now'), " + "%.0f" % velocity + ", " + "%.0f" % heading + ", " + "%.0f" % vert_spd + ")"
+        return "INSERT INTO vectors (icao, seen, speed, heading, vertical) VALUES (" + "%i" % icao24 + ", datetime('now'), " + "%.0f" % velocity + ", " + "%.0f" % heading + ", " + "%.0f" % vert_spd + ")"
       elif subtype == 1:
         [velocity, heading, vert_spd] = self.parseBDS09_1(data)  
-        retstr = "INSERT INTO vectors (icao, seen, speed, heading, vertical) VALUES (" + "%i" % icao24 + ", datetime('now'), " + "%.0f" % velocity + ", " + "%.0f" % heading + ", " + "%.0f" % vert_spd + ")"
+        return "INSERT INTO vectors (icao, seen, speed, heading, vertical) VALUES (" + "%i" % icao24 + ", datetime('now'), " + "%.0f" % velocity + ", " + "%.0f" % heading + ", " + "%.0f" % vert_spd + ")"
       else:
-        retstr = None
-        
-    return retstr
+        raise NoHandlerError