The_Contractor - 6:33 pm on Jul 11, 2007 (gmt 0)

It's almost certainly down to a lack of automated solutions, and I can only imagine that this is a political decision rather than one based on not having the capabilities.

Sure it is, but I believe things can change without changing/abandoning the original intent of the ODP. There are way too many editor and system resources being used on this issue.
A simple "I’m sorry, the URL you suggested has already been suggested for review in CategoryName" or "I’m sorry the URL you suggested is already listed in CategoryName". This would solve multiple problems which all stem from multiple submissions. The problem has been in the conflicting info of "Identify the single best category for your site. The Open Directory has an enormous array of subjects to choose from. You should submit a site to the single most relevant category." and allowing multiple submissions of the same url/site to multiple categories.