diff --git a/core/sys/rtimer.c b/core/sys/rtimer.c
index 3430c4b71..fd63eacab 100644
--- a/core/sys/rtimer.c
+++ b/core/sys/rtimer.c
@@ -42,7 +42,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: rtimer.c,v 1.5 2007/10/23 20:33:19 adamdunkels Exp $
+ * @(#)$Id: rtimer.c,v 1.6 2009/12/08 23:55:17 adamdunkels Exp $
  */
 
 #include "sys/rtimer.h"
@@ -51,7 +51,7 @@
 #ifdef RTIMER_CONF_NUM
 #define LIST_SIZE RTIMER_CONF_NUM
 #else
-#define LIST_SIZE 4
+#define LIST_SIZE 8
 #endif
 
 static struct rtimer *rtimers[LIST_SIZE];
@@ -65,6 +65,8 @@ static u8_t next, firstempty;
 #define PRINTF(...)
 #endif
 
+static struct rtimer *next_rtimer;
+
 /*---------------------------------------------------------------------------*/
 void
 rtimer_init(void)
@@ -79,108 +81,39 @@ rtimer_set(struct rtimer *rtimer, rtimer_clock_t time,
 	   rtimer_clock_t duration,
 	   rtimer_callback_t func, void *ptr)
 {
-  int i;
+  int first = 0;
 
   PRINTF("rtimer_set time %d\n", time);
 
+  if(next_rtimer == NULL) {
+    first = 1;
+  }
+
   rtimer->func = func;
   rtimer->ptr = ptr;
-  
-  /* Check if rtimer queue is full. */
-  if(firstempty == (next - 1) % LIST_SIZE) {
-    PRINTF("rtimer_set: next %d firstempty %d full\n", next, firstempty);
-    return RTIMER_ERR_FULL;
-  }
-  
-  /* Check if it is possible to run this rtimer at the requested
-     time. */
-  for(i = next; i != firstempty;
-      i = (i + 1) % LIST_SIZE) {
 
-    if(rtimers[i] == rtimer) {
-      /* Check if timer is already scheduled. If so, we do not
-	 schedule it again. */
-      return RTIMER_ERR_ALREADY_SCHEDULED;
-      
-    }
-    /* XXX: should check a range of time not just the same precise
-       moment. */
-    if(rtimers[i]->time == time) {
-      PRINTF("rtimer_set: next %d firstempty %d time %d == %d\n",
-	     next, firstempty, rtimers[i]->time, time);
-      return RTIMER_ERR_TIME;
-    }
-  }
-  /* Put the rtimer at the end of the rtimer list. */
   rtimer->time = time;
-  rtimers[firstempty] = rtimer;
-  PRINTF("rtimer_post: putting rtimer %p as %d\n", rtimer, firstempty);
+  next_rtimer = rtimer;
 
-  firstempty = (firstempty + 1) % LIST_SIZE;
-
-  /*  PRINTF("rtimer_post: next %d firstempty %d scheduling soon\n",
-      next, firstempty);*/
-
-  /* Check if this is the first rtimer on the list. If so, we need to
-     run the rtimer_arch_schedule() function to get the ball rolling. */
-  if(firstempty == (next + 1) % LIST_SIZE) {
-    
-    PRINTF("rtimer_set scheduling %d %p (%d)\n",
-	 next, rtimers[next], rtimers[next]->time);
-    rtimer_arch_schedule(rtimers[next]->time);
+  if(first == 1) {
+    rtimer_arch_schedule(time);
   }
-  
   return RTIMER_OK;
 }
 /*---------------------------------------------------------------------------*/
 void
 rtimer_run_next(void)
 {
-  int i, n;
   struct rtimer *t;
-
-  /* Do not run timer if list is empty. */
-  if(next == firstempty) {
+  if(next_rtimer == NULL) {
     return;
   }
-  
-  t = rtimers[next];
-
-  /* Increase the pointer to the next rtimer. */
-  next = (next + 1) % LIST_SIZE;
-  
-  /* Run the rtimer. */
-  PRINTF("rtimer_run_next running %p\n", t);
+  t = next_rtimer;
+  next_rtimer = NULL;
   t->func(t, t->ptr);
-
-  if(next == firstempty) {
-    PRINTF("rtimer_run_next: empty rtimer list\n");
-    /* The list is empty, no more rtimers to schedule. */
-    return;
+  if(next_rtimer != NULL) {
+    rtimer_arch_schedule(next_rtimer->time);
   }
-
-  /* Find the next rtimer to run. */
-  n = next;
-  for(i = next; i != firstempty; i = (i + 1) % LIST_SIZE) {
-    PRINTF("rtimer_run_next checking %p (%d) against %p (%d)\n",
-	   rtimers[i], rtimers[i]->time,
-	   rtimers[n], rtimers[n]->time);
-    if(RTIMER_CLOCK_LT(rtimers[i]->time, rtimers[n]->time)) {
-      n = i;
-    }
-  }
-
-  PRINTF("rtimer_run_next next rtimer is %d %p (%d)\n",
-	 n, rtimers[n], rtimers[n]->time);
-  
-  /* Put the next rtimer first in the rtimer list. */
-  t = rtimers[next];
-  rtimers[next] = rtimers[n];
-  rtimers[n] = t;
-
-  PRINTF("rtimer_run_next scheduling %d %p (%d)\n",
-	 next, rtimers[next], rtimers[next]->time);
-
-  rtimer_arch_schedule(rtimers[next]->time);
+  return;
 }
 /*---------------------------------------------------------------------------*/