Index: tcp_timer.c
===================================================================
--- tcp_timer.c	(revision 237202)
+++ tcp_timer.c	(working copy)
@@ -675,37 +675,34 @@
 	bzero(xtimer, sizeof(struct xtcp_timer));
 	if (timer == NULL)
 		return;
+	binuptime(&now);
+	tmp.sec = 0;
+	tmp.frac = 0;
 	
 	if (callout_active(&timer->tt_delack)) {
-		binuptime(&now);
 		tmp = timer->tt_delack.c_time;		
 		bintime_sub(&tmp,&now);
 		xtimer->tt_delack = bintime_to_msecs(tmp);
 	}
 	
 	if (callout_active(&timer->tt_rexmt)) {
-		binuptime(&now);
 		tmp = timer->tt_rexmt.c_time;
 		bintime_sub(&tmp,&now);
 		xtimer->tt_rexmt = bintime_to_msecs(tmp);
 	}
 	
 	if (callout_active(&timer->tt_persist)) {
-		binuptime(&now);
-		tmp = timer->tt_persist.c_time;
 		bintime_sub(&tmp,&now);
 		xtimer->tt_persist = bintime_to_msecs(tmp);
 	}
 	
 	if (callout_active(&timer->tt_keep)) {
-		binuptime(&now);
 		tmp = timer->tt_keep.c_time;
 		bintime_sub(&tmp,&now); 
 		xtimer->tt_keep = bintime_to_msecs(tmp);
 	}
 
 	if (callout_active(&timer->tt_2msl)) {
-		binuptime(&now);
 		tmp = timer->tt_2msl.c_time;
 		bintime_sub(&tmp,&now);
 		xtimer->tt_2msl = bintime_to_msecs(tmp);