diff -up sysstat-10.0.0/mpstat.c.pom sysstat-10.0.0/mpstat.c
--- sysstat-10.0.0/mpstat.c.pom	2011-03-11 18:09:57.000000000 +0100
+++ sysstat-10.0.0/mpstat.c	2011-04-04 11:22:20.000000000 +0200
@@ -418,6 +418,9 @@ void write_stats_core(int prev, int curr
 
 			/* Recalculate itv for current proc */
 			pc_itv = get_per_cpu_interval(scc, scp);
+			if ((scc->cpu_user - scc->cpu_guest) < (scp->cpu_user - scp->cpu_guest))
+				pc_itv = pc_itv + (scp->cpu_user - scp->cpu_guest) -
+					(scc->cpu_user - scc->cpu_guest);
 			
 			if (!pc_itv) {
 				/*