I have never fallen out of my hammock, but I owned a Ticket to the Moon (I think this brand is very similar to ENO) single hammock for a couple of months and remember that I had the feeling of being kicked out of it initially. I believe that the hang angle was too shallow; an easy mistake to make without a ridgeline. I also wonder if the end-type makes a difference: I found that I prefer gathered end over cinched end.