The balancer will not try balancing the regions when there's only one node.
In my logs, testing 0.95.1 RC1, I see:
2013-06-07 17:31:47,377 DEBUG [ip-10-20-46-44.novalocal,48569,1370640098134-BalancerChore] balancer.StochasticLoadBalancer: Could not find a better load balance plan. Tried 3200 different configurations in 27ms, and did not find anything with a computed cost less than 25.0
Ideally we'd not even try one configuration, let alone 3.2k.