That was it!  There is an iFinity trigger on the modules table called "ifty_OnNewModule" that touches that column.

This is on a test server with version 2.4.4 of the iFinity module.  I see that there is a new release - perhaps Bruce has already changed this in the latest version.  I'll try to do an upgrade later to find out. 

~ Greg

Greg/Cathal, I am just importing a very large site to DotNetNuke as we're so impressed with it, and obviously I have a lot of legacy URLs to bring over. We want to keep the url structure as it is for now to avoid the mass cnofusion of changing them (that will come later), so am I correct in thinking that any new URLs created by DotNetNuke are worked out using the logic and not stored in the database?

And if so would you recommend I extend the Friendly URL provider to honour our old urls or is there a better method?

Thanks Cathal, in case anyone out there has come across the same challenge and is wondering how it went, I decided to extend the DNN friendly URL provider with my own version, which did a simple lookup and store ( in cache) of our set of 'legacy' old urls against TabID, and then also wrote a very simple HttpModule that looks for old URLs in the dictionary and redirects to the associated tabid page