Clusterer Markers

Hi all,

I'm trying to get a handle on Jef Poskanzer's fantastic Cluster script
posted on Mike William's excellent tutorial site
(http://www.econym.demon.co.uk/googlemaps).

I've modifed Mike's example to use my own data but the cluster markers
are not being displayed. The marker itself seems to be present since a
click on the sidebar yields an info window from the "ghost marker".
However, it is not the composite info window that is supposed to be
generated by the clusterer. For some reason the clusterIcon image is
not showing up. I've wasted a bunch of time on this and now I humbly
request the help of anyone willing to offer it. My example can be
found at http://www.gisconsulting.com/gmaps/clusterer.htm.

Many Thanks,

David