Some of the mystery is cleared up - and it is clear there are two different incidents at our house.
John Payne called me up tonight, and told me that when they had cleaned up their house (next one over from us) Sunday morning, they had a load of food left, and assuming we were hung over (they probably heard us the night before), they had brought the food over rather than chucking it out, so that we could have a hardy breakfast.
The bags and paint boxes and other rubbish was not there at that time - and someone else has dumped that later in the day Sunday.
Unfortunately, we had left earlier in the morning to help out the Charms girls on site, so when we returned, the food and the rubbish on the lawn seemed like the same incident - which obviously it wasn't.
So, Thanks to the Ducks for thinking of us, and sorry that you guys were wrongly implicated, when really you tried to do something nice
It still remains however, that someone has removed rubbish from the collection point, and purposely thrown it on our lawn.... and only our lawn.... which seems to indicate it is not a random thing, but done with a purpose.
Nick