diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8594201e..583523e5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,7 +11,6 @@ file(GLOB HEADERS "*.h" "Console/*.h" "McZapkie/*.h")
 
 set(SOURCES
 "Texture.cpp"
-"TextureDDS.cpp"
 "Timer.cpp"
 "Track.cpp"
 "Traction.cpp"
@@ -77,14 +76,12 @@ set(SOURCES
 "audiorenderer.cpp"
 "motiontelemetry.cpp"
 "utilities.cpp"
-"light.cpp"
 "uitranscripts.cpp"
 "station.cpp"
 "application.cpp"
 "simulationtime.cpp"
 "sceneeditor.cpp"
 "screenshot.cpp"
-"combustionengine.cpp"
 "driverkeyboardinput.cpp"
 "drivermode.cpp"
 "driveruilayer.cpp"
diff --git a/PyInt.cpp b/PyInt.cpp
index caa2868c..cee7c8d6 100644
--- a/PyInt.cpp
+++ b/PyInt.cpp
@@ -160,6 +160,18 @@ auto python_taskqueue::insert( task_request const &Task ) -> bool {
     // acquire a lock on the task queue and add a new task
     {
         std::lock_guard<std::mutex> lock( m_tasks.mutex );
+
+        // if task for this target already exists, don't add another
+        for (render_task *task : m_tasks.data)
+            if (task->get_target() == Task.target)
+            {
+                PyEval_AcquireLock();
+                Py_DECREF(Task.input);
+                PyEval_ReleaseLock();
+
+                return false;
+            }
+
         m_tasks.data.emplace_back( new render_task( renderer, Task.input, Task.target ) );
     }
     // potentially wake a worker to handle the new task
diff --git a/PyInt.h b/PyInt.h
index e47a9f62..2120d368 100644
--- a/PyInt.h
+++ b/PyInt.h
@@ -44,6 +44,7 @@ public:
     {}
 // methods
     void run();
+    const texture_handle get_target() const { return m_target; }
 
 private:
 // members
diff --git a/version.h b/version.h
index dcd11012..e2583983 100644
--- a/version.h
+++ b/version.h
@@ -1 +1 @@
-#define VERSION_INFO "M7 12.10.2018, based on tmj-44b652c"
+#define VERSION_INFO "M7 13.10.2018, based on tmj-68f82be4"