As far as I understand it :-
1) DreadLords is the original game engine with the DL scenarios
2) Then came DA, that ugraded the game engine and also upgraded the DL scenarios so you could play the 'old' DL scenarios in the newer game engine.
3) Then came TA, that upgraged the game engine again BUT DID NOT update any of the DL or DA scenarios so they still had to be played in an older game engine then the TA scenarios.
4) Finally version 2 that upgraded the game engine again and updates ALL the scenarios (DL / DA / TA) to work with this new engine.
I am sure there was a sticky / pinned post above that explaned this but it seems to have gone.
