Address Panel in iCal empty but typing in characters yields search results

I upgraded our 10.5 iCal Server to a Snow Leopard server about 6 weeks ago. At that time I also began upgrading users to 10.6 from 10.5. The address panel of iCal functioned properly with 10.5 clients before and after the server upgrade. However the 10.6 clients see nothing in the Address Panel of iCal until they begin entering a name, email address, etc.

If I use the iCal Server utility on my machine I can see resources and conference rooms (locations) that have been setup so I know the information is there and being served. Is this just the operation of 10.6 clients? I would imagine the address panel would populate automatically when opened rather than necessitating the entering of data to perform a lookup.

I feel like I am missing a switch or something simple. Anyone have any ideas?
Other than that issue it all works fine (iCal server with 50+ users scheduling).

Thanks folks.
Bill