Glad it worked for you.

@Glenn. Yes as I was writing that I wondered if that was an alteration in SLT . It comes out of this line in product listing:

Code:
$max_results = (PRODUCT_LISTING_LAYOUT_STYLE=='columns' && PRODUCT_LISTING_COLUMNS_PER_ROW>0) ? (PRODUCT_LISTING_COLUMNS_PER_ROW * (int)(MAX_DISPLAY_PRODUCTS_LISTING/PRODUCT_LISTING_COLUMNS_PER_ROW)) : MAX_DISPLAY_PRODUCTS_LISTING;
Bit as you say it is not a feature of column grid itself. But perhaps Leslie has SLT ( or SNAF) installed rather than the basic column grid.