diff --git a/src/mame/drivers/neodrvr.c b/src/mame/drivers/neodrvr.c
index 0c923f3d1c3..d7df55ede47 100644
--- a/src/mame/drivers/neodrvr.c
+++ b/src/mame/drivers/neodrvr.c
@@ -7160,18 +7160,20 @@ static DRIVER_INIT( kf2k3pcb )
 	kf2k3pcb_gfx_decrypt(machine);
 	kof2003biosdecode(machine);
 
-	/* extra little swap on the m1 */
+	neogeo_cmc50_m1_decrypt(machine);
 
+	/* extra little swap on the m1 - this must be performed AFTER the m1 decrypt
+	   or the m1 checksum (used to generate the key) for decrypting the m1 is
+	   incorrect */
 	{
 		int i;
-		UINT8* rom = memory_region(machine, "audiocrypt");
-		for (i=0;i<0x80000;i++)
+		UINT8* rom = memory_region(machine, "audio");
+		for (i=0;i<0x90000;i++)
 		{
 			rom[i] = BITSWAP8(rom[i], 5, 6, 1, 4, 3, 0, 7, 2);
 		}
 
 	}
-	neogeo_cmc50_m1_decrypt(machine);
 
 	kof2000_neogeo_gfx_decrypt(machine, 0x9d);
 	kf2k3pcb_decrypt_s1data(machine);
diff --git a/src/mame/machine/neocrypt.c b/src/mame/machine/neocrypt.c
index f5a1303008f..bf4fff68d54 100644
--- a/src/mame/machine/neocrypt.c
+++ b/src/mame/machine/neocrypt.c
@@ -1503,8 +1503,7 @@ void neogeo_cmc50_m1_decrypt(running_machine *machine)
 	UINT16 cs16=generate_cs16(rom,0x10000);
 	UINT16 key = BITSWAP16(cs16,12,0,2,4,8,15,7,13,10,1,3,6,11,9,14,5)^0xffff;
 
-	/* HACK! -- something is wrong in kf2k3pcb, is the m1 bad? */
-	if (!strcmp(machine->gamedrv->name,"kf2k3pcb")) key = 0x4b64;
+	//printf("key %04x\n",key);
 
 	for (i=0; i<rom_size; i++)
 	{