3 load balanced web servers, connections not equal

I have 3 web servers behind a load balancer and one of them
consistently has a higher number of connections. I've checked
and the load balancer is configured for round robin balancing
and I've confirmed it's spreading things evenly.

I've run perfmon and connection attempts are equal so I think
that confirms what the load balancer guys are telling me.

Perfmon Current Connections shows a different story. Over
about 6 hours today it had about 36% of the connections with
the other two servers at about 30% and 33%. Also if I check
hits using WebLog Expert (over a week) I get the same
percentages.

My thought was that the server with the most connections is
holding connections longer but I've checked the config and
the connection timeouts are set to the default on all 3
servers. HTTP keep alive is on.

Windows 2003 Std Edition, SP1, current with hotfixes.

Anyone have any ideas on why these connections are not
equal across the servers?

Thanks,
Jim