diff --git a/4J.Render/4J_Render.cpp b/4J.Render/4J_Render.cpp
index 717345839..4516ea575 100644
--- a/4J.Render/4J_Render.cpp
+++ b/4J.Render/4J_Render.cpp
@@ -174,6 +174,15 @@ void C4JRender::DrawVertices(ePrimitiveType PrimitiveType, int count,
 {
     if (count <= 0 || !dataIn) return;
 
+    static int _dbgDVCount = 0;
+    _dbgDVCount++;
+    if (_dbgDVCount <= 10 || (_dbgDVCount % 5000 == 0)) {
+        GLenum err = ::glGetError();
+        fprintf(stderr, "[RENDER] DrawVertices call=%d count=%d prim=%d vType=%d displayList=%d glErr=%d\n",
+            _dbgDVCount, count, (int)PrimitiveType, (int)vType, isCompilingDisplayList(), err);
+        fflush(stderr);
+    }
+
     GLenum mode = mapPrimType((int)PrimitiveType);
     unsigned char *data = (unsigned char *)dataIn;
 
@@ -245,6 +254,13 @@ void C4JRender::CBuffEnd()
 bool C4JRender::CBuffCall(int index, bool /*full*/)
 {
     if (index <= 0) return false;
+    static int _dbgCBCount = 0;
+    _dbgCBCount++;
+    if (_dbgCBCount <= 5 || (_dbgCBCount % 5000 == 0)) {
+        fprintf(stderr, "[RENDER] CBuffCall call=%d index=%d isList=%d\n",
+            _dbgCBCount, index, ::glIsList(index));
+        fflush(stderr);
+    }
     if (::glIsList(index)) { ::glCallList(index); return true; }
     return false;
 }
diff --git a/Minecraft.Client/Rendering/GameRenderer.cpp b/Minecraft.Client/Rendering/GameRenderer.cpp
index 4074cb9fb..b99d11296 100644
--- a/Minecraft.Client/Rendering/GameRenderer.cpp
+++ b/Minecraft.Client/Rendering/GameRenderer.cpp
@@ -995,6 +995,13 @@ int GameRenderer::getLightTexture(int iPad, Level *level)
 
 void GameRenderer::render(float a, bool bFirst)
 {
+	static int _dbgRenderCount = 0;
+	_dbgRenderCount++;
+	if (_dbgRenderCount <= 5 || (_dbgRenderCount % 300 == 0)) {
+		fprintf(stderr, "[RENDER] GameRenderer::render frame=%d level=%p screen=%p width=%d height=%d\n",
+			_dbgRenderCount, (void*)mc->level, (void*)mc->screen, mc->width, mc->height);
+		fflush(stderr);
+	}
 	if( _updateLightTexture && bFirst) updateLightTexture(a);
 	if (Display::isActive())
 	{
@@ -1254,6 +1261,17 @@ void GameRenderer::DisableUpdateThread()
 
 void GameRenderer::renderLevel(float a, __int64 until)
 {
+	static int _dbgRLCount = 0;
+	_dbgRLCount++;
+	if (_dbgRLCount <= 3 || (_dbgRLCount % 300 == 0)) {
+		fprintf(stderr, "[RENDER] renderLevel frame=%d player=%p levelRenderer=%p\n",
+			_dbgRLCount, (void*)mc->player.get(), (void*)mc->levelRenderer);
+		if (mc->player) {
+			fprintf(stderr, "[RENDER]   playerPos=(%.1f, %.1f, %.1f)\n",
+				mc->player->x, mc->player->y, mc->player->z);
+		}
+		fflush(stderr);
+	}
 //	if (updateLightTexture) updateLightTexture();	// 4J - TODO - Java 1.0.1 has this line enabled, should check why - don't want to put it in now in case it breaks split-screen
 
 	glEnable(GL_CULL_FACE);