[chef] Nodes not showing up in search

[Paul Graydon < >]

I seem to be hitting an odd glitch with search in that nodes with a role 
associated with them aren't returning when I search based on role:

$ knife search node role:monitored
1 items found

Node Name:   lana.###.###
Environment: _default
FQDN:        lana.###.###
IP:          ###.###.###.###
Run List:    recipe[ldap], recipe[chef-client::service], role[monitored]
Roles:       monitored
Recipes:     ldap, chef-client::service
Platform:    centos 6.2

If I do a show for a node I know has this role associated with it:

$ knife node show monitor.###.###
Node Name:   monitor.###.###
Environment: _default
FQDN:        monitor.###.###
IP:          ###.###.###.###
Run List:    recipe[chef-client::service], recipe[ntp], recipe[openssh], 
recipe[openssl], role[monitored]
Roles:       monitored
Recipes:     chef-client::service, ntp, openssh, openssl,
Platform:    centos 5.8

Anyone have any ideas what might be causing this odd behaviour? I've 
tried doing "knife index rebuild" and then repeating the process but to 
no avail.  chef-client has been run on all the relevant servers after 
the role has been added.

Paul