He brought home the bacon..
I guess it works all properly now.
Finally I re-installed MODx (because I played around too much with it and I was going lost..).
I guess the problem "Undefined variable..." was just a template issue - don’t know..
Simplest way to start running:
1. Create a (unpublished) Folder where the News will be stored
2. Create a new document with the snippet call:
[[NewsListing? &startID=`<folder id with the news>` &comments=`true` &commentschunk=`FormBlogComments`
3. Create a Chunk and name it FormBlogComments. This chunk should contain at least:
eather:
[!UserComments? &makefolder=`1`!]
or:
[!UserComments? &folder=`<folder where comments are stored>`
4. Place the Chunk at the end of the Articel or rather the news, like as follows:
{{FormBlogComments}}
If have have plenty of time I will write a small how-to with screenshots.
And if Mark found the time to write a small example I can also translate it for the german community - if desired.