TOPIC: Upgrade from 2.7.10 to 2.5.8...HELP! :-)

We love dtregister but have had allot of issues with trying to upgrade.
Hensce we are still stuck on 2.7 and have adev site which we updated but we lost all the records and are unable to complete a transaction. I am sure it is a permissions issue but we followed the driections to a T.....except for the burning question....
When going from 2.7.1 to 2.8.5 on a 1.7 site do you need to uninstall?
(chicken or the egg)
Is there any other tricks as we have tried to upgrade 5 times now and everytime it breaks the registration system so that noone can go farther than the step of filling in info. We tried upgrading dt first then going up to J2.5.8 and that did not help. I know there is a major difference in permissions between 1.7 and 2.5 and that extra tables and permissions are added which can be a real mess. I implore the community to give us a little guidance on this as the client loves the system, taking 3 to 6 registrations a day and we cannot be down for very long....

You should not need to uninstall first, but it shouldn't matter either way. I would however first upgrade your Joomla site. You certainly shouldn't be using 1.7 still.

Sounds to me like you have a conflict happening. Users can't advance in the registration process? Do you see any errors show in Firebug (within Firefox)? You likely have a conflict with JQuery usage or something like that. Make sure your template or any other components/plugins are not compressing or replacing the DT Register scripts with some other version. That's my guess and suggestion for a direction to pursue.