Mongrel_rails won't run

I installed mongrel and mongrel_cluster and then tried to run
mongrel_rails and got the following error:

no such file to load – http11 (LoadError)

I am trying to run mongrel_rails cluster::configure …options… on a
windows pc.

I have mongrel-0.3.13.4 for ruby
and mongrel_cluster-0.2.1

Anyone have any ideas?

Thanks in advance,

Sam