remove vtimer object before (re)scheduling it

sys/net/destiny/tcp_timer.c

@@ -154,6 +154,7 @@ void tcp_general_timer(void)
     while (1) {
         inc_global_variables();
         check_sockets();
+        vtimer_remove(&tcp_vtimer);
         vtimer_set_wakeup(&tcp_vtimer, interval, thread_getpid());
         thread_sleep();
     }

sys/net/sixlowpan/flowcontrol.c

@@ -118,6 +118,7 @@ static int set_timeout(vtimer_t *timeout, long useconds, void *args)
     interval.seconds = useconds / 1000000;
     interval.microseconds = (useconds % 1000000) * 1000;
 
+    vtimer_remove(timeout);
     return vtimer_set_msg(timeout, interval, sending_slot_pid, args);
 }