I have read all of the threads on helping to get your ferrets to poop in the box.  We have a 3 year old male and female.  The female seems to have finally gotten going in the box and the male was hit and miss and now all of the sudden he refuses to go in the boxes.  We have three of them in the pen and have put new paper on the ground because he won't go in the box.  We have two corner boxes and one cat box that I cut the side down so it is easy to get into.  I have been using blue buffalo crushed walnut pellet which has been great, there is no stink and the female has no problem with it and the male has been so so with it.  I have started to wonder if the litter is bothering him and I should try something else, but I don't know what would be a good litter for them.  If anyone has suggestions I would love it.  We reward them when they go in the box and I think that is what got the female to go we also keep the boxes clean.  The male will go by his bedding, his food and it doesn't have to be a corner either.  He has gone on stuffed animals as well.  My husband is ready to get rid of them which will make the boys very sad but between the male and his box problem and the female bites I can't blame him any more.