[TYPO3-shop] Category 'and' combinations

[Jogvan Olsen]

Hi


I have a category tree like this.

Color (id=1)
    - black (id=2)
    - gray (id=3)
    - red (id=4)
Luster (id=5)
    - glossy (id=6)
    - semi gloss (id=7)
    ...

On a page I want to show ONLY 'black' AND 'semi gloss' products - Is it 
possibly?

If I add this to my setup:
plugin.tt_products.defaultCategoryID =  2,7
I get all black products (glossy, semi gloss,...) and all semi gloss 
products (black, gray, red, ...). I only want product that are back and 
semi gloss - how can I get that?

I use
TYPO3 ver. 4.2.6
tt_products ver 2.8.0


regards
Jogvan Olsen