@libertyforall1776:
I understand what you mean! In the latest versions from Transmission the Developers decided to add Leopard technology. Just to be clear, I also understand the developers! At some point you choose to integrate new technology, which is in this case Leopard only, and to mature the program or to follow the pad of natural evolution you've planned for this great program.

I have a few Macs which are running Leopard. I also have older Macs, which are still in very good shape and which are running on a daily base, not capable to run Leopard.
I solved this issue with previous versions from Transmission, which are all stored on a server!

That is a great service almost unique for this application! Thanks to the guys who are running this server (I think they are the developers from Transmission, but I'm not sure)!!!
Here is the link where you can find "every" version between 2007 and today:

http://transmission.xpjets.com/OLD/

I realy hope this information will help you to keep running Transmisson, which is a fantastic program, on your Pre Leopard Macs (like in my case).

With regards.