Please, first of all, delete any old aulawiki version you have installed in your site, Ensure (through ftp, if needd) that there is not any file ./mods/Packages/features-aulawiki.info.txt in your site, nor any other under ./mods subfolders called aulawiki*.* (remove those files manually if still in there)
Then try using the automatic install which I explained above (Using AulaWiki 1.6.2 from edu.tw.o/mods.). I tested it and worked fine for me on a clean install based on 2.x.
You don't need to install manually.
You can install the 1.6.2 version (updated, working except that not a nice display) from this mods repository:
Mods remote server: http://edu.tikiwiki.org/mods
See AulaWiki for more information.
Hope this helps.