I had the same problem with my 3800 and using paper paper cut from a roll. I came to the conclusion that I had not cut the paper absolutely square, and that the printer was reading a smaller paper size than was there.
If you print when no paper is under the head ink will NOT go to the Maintenance Tank. There are pads across the print platen of the printer that are spaced for specific BorderFree sizes. These are engineered to be at the edge of each size to route excess ink to the tank. These pads are visible under the top front cover. The balance of the excess ink will sit on the platen and can be a challenge to clean.