Automatic Litterbox Central

I had a traditional covered litter box, and my cat Benji would pee on the wall of it, and that would make a mess outside the box. Has anyone had a similar problem with the Omega Paws unit?

Thanks in advance!

My cats don't pee on the sides of the box (traditional or the OP)... That said, the seal is pretty good between the two parts, so I wouldn't think that it would go outside the box (from the inside).

Art