diff --git a/cpu/msp430/clock.c b/cpu/msp430/clock.c
index 23f60854f..c8781a7ce 100644
--- a/cpu/msp430/clock.c
+++ b/cpu/msp430/clock.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: clock.c,v 1.19 2009/12/09 12:55:35 adamdunkels Exp $
+ * @(#)$Id: clock.c,v 1.20 2010/01/18 21:17:11 adamdunkels Exp $
  */
 
 
@@ -57,15 +57,15 @@ interrupt(TIMERA1_VECTOR) timera1 (void) {
 
   if(TAIV == 2) {
 
-    eint();
-
     /* HW timer bug fix: Interrupt handler called before TR==CCR.
      * Occurrs when timer state is toggled between STOP and CONT. */
     while(TACTL & MC1 && TACCR1 - TAR == 1);
 
     /* Make sure interrupt time is future */
     do {
+      TACTL &= ~MC1;
       TACCR1 += INTERVAL;
+      TACTL |= MC1;
       ++count;
 
       /* Make sure the CLOCK_CONF_SECOND is a power of two, to ensure
@@ -88,6 +88,7 @@ interrupt(TIMERA1_VECTOR) timera1 (void) {
       etimer_request_poll();
       LPM4_EXIT;
     }
+
   }
   /*  if(process_nevents() >= 0) {
     LPM4_EXIT;
diff --git a/cpu/msp430/rtimer-arch.c b/cpu/msp430/rtimer-arch.c
index 96c802ed6..3d4aeacc7 100644
--- a/cpu/msp430/rtimer-arch.c
+++ b/cpu/msp430/rtimer-arch.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rtimer-arch.c,v 1.11 2009/12/08 23:39:45 adamdunkels Exp $
+ * $Id: rtimer-arch.c,v 1.12 2010/01/18 21:17:11 adamdunkels Exp $
  */
 
 /**
@@ -81,6 +81,8 @@ void
 rtimer_arch_schedule(rtimer_clock_t t)
 {
   PRINTF("rtimer_arch_schedule time %u\n", t);
-  
+
+  TACTL &= ~MC1;
   TACCR0 = t;
+  TACTL |= MC1;
 }