I'm sorry to see the problems reported. I have no idea myself, about what or where is the problem. It worked for me strait ahead from admin mods web interface, on one server, and on another, where there is a strange perms. configuration, we couldn't through we interface, and I ended up installing it by hand (as you did, btw .
Being said this, I had to request to the server admin to install some module (bablotron, as far as I remember) for tikidav to work. But once that was installed, tikidav works (taking into consideration that's not a finished work by his author, jreyes).
I would say, write to the author directly (he might not be reading this forum), and he's rather busy, but he'll end up answering you, for sure (and maybe fixing this problem for you?). jreyes at escire.com
Cheers, and good luck!
P.D: I hope you've seen AulaWiki and try it for your educational purposes (I'm planing to use it for production next course with some of my students also)