I had the same problem with mine. I did, however, have 1/8" pegs through the inner side of the gunwales and then through the rib. Even with this peg in place several of the ribs did split at the end and were then able to pop out. In the end I used some staples (dear God forgive me) on those that were popping out the most in order to hold them in while i skinned the kayak. Once the skin was shrunk there were no problems.

I think you will find that the skin will keep everything together.

: My SOF if just about ready to be skinned but if i sit in it the
: ribs pop out?! The ribs are rounded (not squared). If I lash the
: ribs to the gunales I am worried that the rib stock will just
: spit where I drill the hole. My brother thinks that the skin
: will hold it all together in the end. Is that a safe assumption
: or should I get this figured out before I skin it? Any
: suggestions would be greatly appreciated.