diff --git a/src/hardware/timer.cpp b/src/hardware/timer.cpp
index 06a83a8b..17565188 100644
--- a/src/hardware/timer.cpp
+++ b/src/hardware/timer.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: timer.cpp,v 1.32 2005-03-25 11:52:32 qbix79 Exp $ */
+/* $Id: timer.cpp,v 1.33 2005-08-07 17:33:15 qbix79 Exp $ */
 
 #include <math.h>
 #include "dosbox.h"
@@ -121,6 +121,7 @@ static void counter_latch(Bitu counter) {
 
 
 static void write_latch(Bitu port,Bitu val,Bitu iolen) {
+//LOG(LOG_PIT,LOG_ERROR)("port %X write:%X state:%X",port,val,pit[port-0x40].write_state);
 	Bitu counter=port-0x40;
 	PIT_Block * p=&pit[counter];
 	if(p->bcd == true) BIN2BCD(p->write_latch);
@@ -152,7 +153,7 @@ static void write_latch(Bitu port,Bitu val,Bitu iolen) {
 		switch (counter) {
 		case 0x00:			/* Timer hooked to IRQ 0 */
 			if (p->new_mode || p->mode == 0 ) {
-				p->new_mode=false;			
+				p->new_mode=false;
 				PIC_AddEvent(PIT0_Event,p->delay);
 			} else LOG(LOG_PIT,LOG_NORMAL)("PIT 0 Timer set without new control word");
 			LOG(LOG_PIT,LOG_NORMAL)("PIT 0 Timer at %.2f Hz mode %d",1000.0/p->delay,p->mode);
@@ -168,6 +169,7 @@ static void write_latch(Bitu port,Bitu val,Bitu iolen) {
 }
 
 static Bitu read_latch(Bitu port,Bitu iolen) {
+//LOG(LOG_PIT,LOG_ERROR)("port read %X",port);
 	Bit32u counter=port-0x40;
 	if (pit[counter].go_read_latch == true) 
 		counter_latch(counter);
@@ -204,6 +206,7 @@ static Bitu read_latch(Bitu port,Bitu iolen) {
 }
 
 static void write_p43(Bitu port,Bitu val,Bitu iolen) {
+//LOG(LOG_PIT,LOG_ERROR)("port 43 %X",val);
 	Bitu latch=(val >> 6) & 0x03;
 	switch (latch) {
 	case 0:
@@ -220,15 +223,28 @@ static void write_p43(Bitu port,Bitu val,Bitu iolen) {
 		} else {
 			pit[latch].read_state  = (val >> 4) & 0x03;
 			pit[latch].write_state = (val >> 4) & 0x03;
-			pit[latch].mode        = (val >> 1) & 0x07;
-			if (pit[latch].mode>5)
-				pit[latch].mode-=4; //6,7 become 2 and 3
-			if (latch==0) {
+			Bit8u mode             = (val >> 1) & 0x07;
+			/* Don't set it directly so counter_output uses the old mode */
+
+			/* If the line goes from low to up => generate irq. 
+			 *      ( BUT needs to stay up until acknowlegded by the cpu!!! therefore: )
+			 * If the line goes to low => disable irq.
+			 * Mode 0 starts with a low line. (so always disable irq)
+			 * Mode 2,3 start with a high line.
+			 * counter_output tells if the current counter is high or low 
+			 * So actually a mode 2 timer enables and disables irq al the time. (not handled) */
+
+			if (mode > 5)
+				mode -= 4; //6,7 become 2 and 3
+			if (latch == 0) {
 				PIC_RemoveEvents(PIT0_Event);
-				if (!counter_output(0) && pit[latch].mode)
+				if (!counter_output(0) && mode)
 					PIC_ActivateIRQ(0);
+				if(!mode)
+					PIC_DeActivateIRQ(0);
 			}
-			pit[latch].new_mode	   = true;
+			pit[latch].new_mode = true;
+			pit[latch].mode     = mode; //Set the correct mode (here)
 		}
 		break;
     case 3: