[NTG-context] \writebetweenllst not working for frontmatter material?

[robheus]

hello list,

I want a TOC in which there is a blank line AFTER the first chapter in 
the TOC and BEFORE the last chapter in the TOC. (other chapter entries 
in the TOC don't have blank lines between them).

I can achieve this with:
\writebetweenlist[chapter]{\blank}

but unfortutaly for chapter in frontmatter the above method does not 
produce a blank line in the TOC.

Anyone has a clue as why not?

Greetings,

Rob