diff -up linux-2.6.32-33.planetlab.x86_64/kernel/sched.c.orig linux-2.6.32-33.planetlab.x86_64/kernel/sched.c
--- linux-2.6.32-33.planetlab.x86_64/kernel/sched.c.orig	2012-08-29 05:08:16.000000000 -0400
+++ linux-2.6.32-33.planetlab.x86_64/kernel/sched.c	2012-08-29 05:25:03.150631094 -0400
@@ -4058,6 +4058,9 @@ static void update_group_power(struct sc
 		group = group->next;
 	} while (group != child->groups);
 
+    if (!power)
+		power = 1;
+
 	sdg->cpu_power = power;
 }