diamondTears: glad to have cleared things up a bit.
Zachary: I am now further into my project than I was when I wrote this post and I repent entirely the decision to inherit from the table_row classes!! I'll be writing another post when I've settled a bit more with the whole concept but suffice to say I've got ordinary models with SQL or use of Zend_Db stuff in the various methods and that is working much better! They do say "you live and learn" and I did on this one :)
Simon: Thanks for sharing the link. I agree that ORMs can be more hazard than help - especially since I know a lot more about databases than about PHP frameworks.