seems clearer this way

stepmania/src/ScreenManager.cpp

@@ -581,12 +581,8 @@ void ScreenManager::RunConcurrentlyPrepareScreen()
 	m_OnDonePreparingScreen = SM_None;
 
 	/* If the screen is already prepared, we're all set. */
-	if( ScreenIsPrepped(sScreenName) )
+	if( !ScreenIsPrepped(sScreenName) )
 	{
-		SendMessageToTopScreen( SM );
-		return;
-	}
-
 		g_bIsConcurrentlyLoading = true;
 		StartConcurrentRendering();
 
@@ -597,6 +593,7 @@ void ScreenManager::RunConcurrentlyPrepareScreen()
 		g_bIsConcurrentlyLoading = false;
 
 		LOG->Trace( "Concurrent prepare of %s finished", sScreenName.c_str() );
+	}
 
 	/* We're done.  Send the message.  The screen is allowed to start
 	 * another concurrent prepare from this message. */