diff --git a/src/mame/drivers/kongambl.c b/src/mame/drivers/kongambl.c
index 40108a882c6..0c6f71bb9f1 100644
--- a/src/mame/drivers/kongambl.c
+++ b/src/mame/drivers/kongambl.c
@@ -531,7 +531,7 @@ static MACHINE_CONFIG_START( kongambl, kongambl_state )
 
 	MCFG_SCREEN_ADD("screen", RASTER)
 	MCFG_SCREEN_REFRESH_RATE(60)
-	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(0))
+	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500))
 	MCFG_SCREEN_SIZE(64*8, 32*8+16)
 	MCFG_SCREEN_VISIBLE_AREA(0*8, 64*8-1, 0*8, 32*8-1)
 	MCFG_SCREEN_UPDATE_STATIC(kongambl)
@@ -679,9 +679,9 @@ static DRIVER_INIT( kingtut )
 	kongambl_state *state = machine.driver_data<kongambl_state>();
 	UINT32 *rom = (UINT32*)state->memregion("maincpu")->base();
 
-	rom[0x3986c/4] = (rom[0x3986c/4] & 0xffff0000) | 0x600e; // patch ROM check
-	rom[0x2bfc8/4] = (rom[0x2bfc8/4] & 0xffff0000) | 0x6612; // patch VRAM ROM checks
-	rom[0x2acd0/4] = (rom[0x2acd0/4] & 0xffff) | 0x6612<<16; // patch OBJ ROM checks
+//	rom[0x3986c/4] = (rom[0x3986c/4] & 0xffff0000) | 0x600e; // patch ROM check
+//	rom[0x2bfc8/4] = (rom[0x2bfc8/4] & 0xffff0000) | 0x6612; // patch VRAM ROM checks
+//	rom[0x2acd0/4] = (rom[0x2acd0/4] & 0xffff) | 0x6612<<16; // patch OBJ ROM checks
 	rom[0x55e40/4] = (rom[0x55e40/4] & 0xffff0000) | 0x4e71; // goes away from the POST
 }