Identical strings are combining together

Hi,

When I print my report, items with the same description are combining together.

For example: I have an item Called "200x300 timber" I also have another item (with a different quantity) called "200x300 timber" because I need 2 different lengths of the timber.

How can I stop these from combining?

(note: when i right click on string and choose format field i can see that "suppress if duplicated" is not ticked).

Any help would be greatly appreciated.