MapOfLondon solved problems caused by missing dbf file
Thanks to Greg for providing the log from the server to help me identify the problem.
MapOfLondon server throwing errors:
[error] Tue Mar 18 11:35:58 2008 - msDBFGetItemIndex(): DBASE file error. Invalid record number 281., referer: http://mapoflondon.uvic.ca/imap/htdocs/
because the file imap/user/data/Agas_Feature_Wards.dbf file is missing. That file is missing because in the "create shape file" interface in the imap admin tool, I specified "Agas_Feature_Wards.shp" as the name of the shape file. When I did that, no .dbf file was generated. When I specified "Agas_Feature_Wards", then both the .shp and .dbf file are created.
This solved the problem of the never-ending back-and-forth between the page and the server, which slowed interfered with all other communication between page and server (e.g. get info on clicked point).