This doesn't really affect me since at this time I don't use confirmation number for anything. But since it may affect others I thought I would bring it to your attention.
I noticed that when I added an individual registration from the backend, it gave a confirmation number with the default "DT-" prefix even though all the ones added on the frontend started with "SEC" as I had set it. I don't use those numbers for anything but I changed the prefix when I was tinkering with the setup.
Also, off topic and probably asked way too much already, any tentative date for 2.7 and possible list of changes? I have a few things I would like DTRegister to do that it currently doesn't. I have considered making small changes to the code to accomplish this but if the update is going to be addressing this then I'd rather wait so I do mess anything up.
Thanks again for what I consider the most promising of all the Registration extensions.