ScreenBranch shouldn't try to load a background

stepmania/src/Screen.h

@@ -35,6 +35,7 @@ public:
 	void ClearMessageQueue( const ScreenMessage SM );	// clear of a specific SM
 
 	bool IsTransparent() const { return m_bIsTransparent; }
+	virtual bool UsesBackground() const { return true; }	// override and set false if this screen shouldn't load a background
 
 	static bool ChangeCoinModeInput( const DeviceInput& DeviceI, const InputEventType type, const GameInput &GameI, const MenuInput &MenuI, const StyleInput &StyleI );	// return true if CoinMode changed
 	static bool JoinInput( const DeviceInput& DeviceI, const InputEventType type, const GameInput &GameI, const MenuInput &MenuI, const StyleInput &StyleI );	// return true if a player joined

stepmania/src/ScreenBranch.h

@@ -12,6 +12,8 @@ public:
 
 	virtual void HandleScreenMessage( const ScreenMessage SM );
 
+	virtual bool UsesBackground() const { return false; }
+
 private:
 	CString m_sChoice;
 };

stepmania/src/ScreenManager.cpp

@@ -338,6 +338,8 @@ retry:
 
 
 	// Load shared BGAnimation
+	if( pNewScreen->UsesBackground() )
+	{
 		CString sNewBGA = THEME->GetPathToB(sScreenName+" background");
 		if( m_sLastLoadedBackground != sNewBGA )
 		{
@@ -350,7 +352,7 @@ retry:
 
 			m_sLastLoadedBackground = sNewBGA;
 		}
-	
+	}	
 
 	if( pOldTopScreen!=NULL  &&  m_ScreenStack.back()!=pOldTopScreen )
 	{