diff --git a/desmume/src/MMU.cpp b/desmume/src/MMU.cpp
index 7a2046131..74dafe124 100644
--- a/desmume/src/MMU.cpp
+++ b/desmume/src/MMU.cpp
@@ -2460,30 +2460,27 @@ u32 DmaController::read32()
 
 static INLINE void write_auxspicnt(const int proc, const int size, const int adr, const int val)
 {
-	//why val==0 to reset? is it a particular bit? its not bit 6...
+	//u16 oldCnt = MMU.AUX_SPI_CNT;
+	bool csOld = (MMU.AUX_SPI_CNT & (1 << 6))?true:false;
 
 	switch(size)
 	{
 		case 16:
 			MMU.AUX_SPI_CNT = val;
-			if (val == 0)
-			{
-				//you know.. its strange. according to gbatek, this should get cleared before the last transfer.
-				//we've got it coded in such a way that it sort of terminates the transfer (is it getting reset immediately before a new transfer?)
-				slot1_device->auxspi_reset(proc);
-			}
 			break;
 		case 8:
-			switch(adr)
-			{
-				case 0: 
-					T1WriteByte((u8*)&MMU.AUX_SPI_CNT, 0, val); 
-					if (val == 0) slot1_device->auxspi_reset(proc);
-					break;
-				case 1: 
-					T1WriteByte((u8*)&MMU.AUX_SPI_CNT, 1, val); 
-					break;
-			}
+			T1WriteByte((u8*)&MMU.AUX_SPI_CNT, adr, val); 
+			break;
+	}
+
+	bool cs = (MMU.AUX_SPI_CNT & (1 << 6))?true:false;
+
+	//printf("MMU%c: cnt %04X, old %04X\n", proc?'7':'9', MMU.AUX_SPI_CNT, oldCnt);
+	
+	if (!cs && csOld)
+	{
+		//printf("MMU%c: CS changed from HIGH to LOW *****\n", proc?'7':'9');
+		slot1_device->auxspi_reset(proc);
 	}
 }
 
@@ -3115,7 +3112,7 @@ bool validateIORegsRead(u32 addr, u8 size)
 				return true;
 
 			default:
-				//printf("MMU9 read%02d from undefined register %08Xh = %08Xh (PC:%08X)\n", size, addr, T1ReadLong(MMU.ARM9_REG, addr & 0x00FFFFFF), ARMPROC.instruct_adr);
+				printf("MMU9 read%02d from undefined register %08Xh = %08Xh (PC:%08X)\n", size, addr, T1ReadLong(MMU.ARM9_REG, addr & 0x00FFFFFF), ARMPROC.instruct_adr);
 				return false;
 		}
 	}
@@ -3788,7 +3785,7 @@ void FASTCALL _MMU_ARM9_write16(u32 adr, u16 val)
 			}
 
 			case REG_AUXSPICNT:
-				write_auxspicnt(9, 16, 0, val);
+				write_auxspicnt(ARMCPU_ARM9, 16, 0, val);
 				return;
 
 			case REG_AUXSPIDATA:
@@ -4835,7 +4832,7 @@ void FASTCALL _MMU_ARM7_write08(u32 adr, u8 val)
 
 			case REG_AUXSPICNT:
 			case REG_AUXSPICNT+1:
-				write_auxspicnt(7, 8, adr & 1, val);
+				write_auxspicnt(ARMCPU_ARM7, 8, adr & 1, val);
 				return;
 
 			case REG_AUXSPIDATA:
@@ -4946,7 +4943,7 @@ void FASTCALL _MMU_ARM7_write16(u32 adr, u16 val)
 
 
 			case REG_AUXSPICNT:
-				write_auxspicnt(7, 16, 0, val);
+				write_auxspicnt(ARMCPU_ARM7, 16, 0, val);
 			return;
 
 			case REG_AUXSPIDATA:
diff --git a/desmume/src/addons/slot1comp_mc.cpp b/desmume/src/addons/slot1comp_mc.cpp
index 035cfb3a1..3b5cd7969 100644
--- a/desmume/src/addons/slot1comp_mc.cpp
+++ b/desmume/src/addons/slot1comp_mc.cpp
@@ -26,7 +26,7 @@ Slot1Comp_MC g_Slot1Comp_MC;
 
 u8 Slot1Comp_MC::auxspi_transaction(int PROCNUM, u8 value)
 {
-	return MMU_new.backupDevice.data_command((u8)value,ARMCPU_ARM9);
+	return MMU_new.backupDevice.data_command(value, PROCNUM);
 }
 void Slot1Comp_MC::auxspi_reset(int PROCNUM)
 {
diff --git a/desmume/src/mc.cpp b/desmume/src/mc.cpp
index 329d7935f..264a60391 100644
--- a/desmume/src/mc.cpp
+++ b/desmume/src/mc.cpp
@@ -28,6 +28,7 @@
 #include "NDSSystem.h"
 #include "utils/advanscene.h"
 
+//#define _ENABLE_MOTION
 
 #define BM_CMD_AUTODETECT       0xFF
 #define BM_CMD_WRITESTATUS      0x01
@@ -106,7 +107,7 @@ void backup_setManualBackupType(int type)
 
 bool BackupDevice::save_state(EMUFILE* os)
 {
-	u32 version = 2;
+	u32 version = 3;
 	//v0
 	write32le(version,os);
 	write32le(write_enable,os);
@@ -121,6 +122,8 @@ bool BackupDevice::save_state(EMUFILE* os)
 	//v2
 	write8le(motionInitState,os);
 	write8le(motionFlag,os);
+	//v3
+	writebool(reset_command_state,os);
 	return true;
 }
 
@@ -142,12 +145,18 @@ bool BackupDevice::load_state(EMUFILE* is)
 	}
 	if(version>=1)
 		read32le(&addr,is);
+	
 	if(version>=2)
 	{
 		read8le(&motionInitState,is);
 		read8le(&motionFlag,is);
 	}
 
+	if(version>=3)
+	{
+		readbool(&reset_command_state,is);
+	}
+
 	return true;
 }
 
@@ -182,6 +191,7 @@ void BackupDevice::reset_hardware()
 	motionInitState = MOTION_INIT_STATE_IDLE;
 	motionFlag = MOTION_FLAG_NONE;
 	state = DETECTING;
+	reset_command_state = false;
 	flushPending = false;
 	lazyFlushPending = false;
 }
@@ -223,17 +233,9 @@ u8 BackupDevice::searchFileSaveType(u32 size)
 	return 0xFF;
 }
 
-void BackupDevice::reset_command()
+void BackupDevice::detect()
 {
-	//printf("MC RESET\n");
-	//for a performance hack, save files are only flushed after each reset command
-	//(hopefully, after each page)
-	if(flushPending)
-	{
-		flush();
-		flushPending = false;
-		lazyFlushPending = false;
-	}
+	if (!reset_command_state) return;
 
 	if(state == DETECTING && data_autodetect.size()>0)
 	{
@@ -285,13 +287,33 @@ void BackupDevice::reset_command()
 		data_autodetect.resize(0);
 		flush();
 	}
-
-	com = 0;
 }
+
+void BackupDevice::checkReset()
+{
+	if (reset_command_state)
+	{
+		//printf("MC  : reset command\n");
+
+		//for a performance hack, save files are only flushed after each reset command
+		//(hopefully, after each page)
+		if(flushPending)
+		{
+			flush();
+			flushPending = false;
+			lazyFlushPending = false;
+		}
+		
+		com = 0;
+		reset_command_state = false;
+	}
+}
+
 u8 BackupDevice::data_command(u8 val, int cpu)
 {
-	//printf("MC CMD: (%02X) %02X\n",com,val);
+	//printf("MC%c : cmd %02X, val %02X\n", cpu?'7':'9', com, val);
 
+#ifdef _ENABLE_MOTION
 	//motion: some guessing here... hope it doesn't break anything
 	if(com == BM_CMD_READLOW && motionInitState == MOTION_INIT_STATE_RECEIVED_4_B && val == 0)
 	{
@@ -306,6 +328,7 @@ u8 BackupDevice::data_command(u8 val, int cpu)
 	{
 		return 0;
 	}
+#endif
 
 	if(com == BM_CMD_READLOW || com == BM_CMD_WRITELOW)
 	{
@@ -320,6 +343,7 @@ u8 BackupDevice::data_command(u8 val, int cpu)
 			//just buffer the data until we're no longer detecting
 			data_autodetect.push_back(val);
 			val = 0;
+			detect();
 		}
 		else
 		{
@@ -359,6 +383,7 @@ u8 BackupDevice::data_command(u8 val, int cpu)
 				}
 				addr++;
 
+				checkReset();
 			}
 		}
 	}
@@ -366,6 +391,7 @@ u8 BackupDevice::data_command(u8 val, int cpu)
 	{
 		//handle request to read status
 		//LOG("Backup Memory Read Status: %02X\n", write_enable << 1);
+		checkReset();
 		return (write_enable << 1) | (3<<2);
 	}
 	else
@@ -375,6 +401,7 @@ u8 BackupDevice::data_command(u8 val, int cpu)
 		{
 			case 0: break; //??
 
+#ifdef _ENABLE_MOTION
 			case 0xFE:
 				if(motionInitState == MOTION_INIT_STATE_IDLE) { motionInitState = MOTION_INIT_STATE_FE; return 0; }
 				break;
@@ -402,28 +429,36 @@ u8 BackupDevice::data_command(u8 val, int cpu)
 					return 0;
 				}
 				break;
+#endif
 
-			case 8:
+			case 0x08:	// IrDA - Pokemon HG/SS
 				printf("COMMAND%c: Unverified Backup Memory command: %02X FROM %08X\n",(cpu==ARMCPU_ARM9)?'9':'7',val, (cpu==ARMCPU_ARM9)?NDS_ARM9.instruct_adr:NDS_ARM7.instruct_adr);
 				val = 0xAA;
+
+				checkReset();
 				break;
 
 			case BM_CMD_WRITEDISABLE:
+#ifdef _ENABLE_MOTION
 				switch(motionInitState)
 				{
 				case MOTION_INIT_STATE_IDLE: motionInitState = MOTION_INIT_STATE_RECEIVED_4; break;
 				case MOTION_INIT_STATE_RECEIVED_4: motionInitState = MOTION_INIT_STATE_RECEIVED_4_B; break;
 				}
+#endif
 				write_enable = FALSE;
+				checkReset();
 				break;
 							
 			case BM_CMD_READSTATUS:
 				com = BM_CMD_READSTATUS;
 				val = (write_enable << 1) | (3<<2);
+				checkReset();
 				break;
 
 			case BM_CMD_WRITEENABLE:
 				write_enable = TRUE;
+				checkReset();
 				break;
 
 			case BM_CMD_WRITELOW:
@@ -456,8 +491,10 @@ u8 BackupDevice::data_command(u8 val, int cpu)
 				break;
 		} //switch(val)
 
+#ifdef _ENABLE_MOTION
 		//motion control state machine broke, return to ground
 		motionInitState = MOTION_INIT_STATE_IDLE;
+#endif
 	}
 	return val;
 }
diff --git a/desmume/src/mc.h b/desmume/src/mc.h
index 5001f855d..80e6c6d03 100644
--- a/desmume/src/mc.h
+++ b/desmume/src/mc.h
@@ -76,7 +76,7 @@ public:
 	bool load_state(EMUFILE* is);
 	
 	//commands from mmu
-	void reset_command();
+	void reset_command() { reset_command_state = true; };
 	u8 data_command(u8,int);
 	std::vector<u8> data;
 
@@ -123,9 +123,12 @@ public:
 
 	bool isMovieMode;
 private:
+	void detect();
+
 	std::string filename;
 	
 	bool write_enable;	//is write enabled?
+	bool reset_command_state;
 	u32 com;	//persistent command actually handled
 	u32 addr_size, addr_counter;
 	u32 addr;
@@ -155,6 +158,8 @@ private:
 
 	void resize(u32 size);
 	void resize(u32 size, u8 val);
+
+	void checkReset();
 };