In jsNotesView2.1.7 there is a problem in a if-clause, related to checking, if a twistie image should displayed:
The line is 1228, with contents:
"}else if(entry.isCategory || (entry.hasChildren && this.responseColumn == x-1)){"
Problem is as follows: it's possible that you have an entry which actually has children but you have no responseColumn at all..! Then this entry IS expandable in a "real" notes view, but not in NotesView2, cause the if-clause can't ever be true. So you see this entry, but you can't get one layer down by expanding it.
My solution is (in NotesView2.1.6 but it's the same for 2.1.7 i think) to add one check:
"}else if(entry.isCategory || (entry.hasChildren && this.responseColumn == x-1)
|| (entry.hasChildren && !entry.twistie) ) {"
This line ensures, that just one twistie image in a row is displayed if there are children in one entry.
Hope this is useful for you and many thanks to you for working on NotesView2 - it saved me a lot of time..! =)
Stefan