I had some similar issues with my Wave traveler kit. The kit is an extremely useful thing to have on your boat and I recommend it for everyone as it gives greater control over your sailing and your sail shape. It turns your Wave from a toy into a sailboat!
The kit comes with a plastic "Accessory mounting plate" which is meant to be riveted to your cross bar.
It seemed a bit odd to me for the swivel cleat to be screwed/bolted onto the plastic piece, then the plastic piece secured with just one rivet to the crossbar to take the entire load from the traveller (rather than attaching the swivel cam directly to the boat).
I found that the screws provided were too short to thread through the metal baseplate and the plastic mount, into the metal of the crossbar. Perhaps I set it up wrong in the first place but I followed the instructions pretty carefully. Then I put an extra couple of rivets through the mounting plate to secure it. That's probably what weakened the plastic further and caused it to break.
Anyway as you can see in the photos here (via Youtube) the plastic mount broke so I ended up mounting the baseplate directly onto the crosspiece with rivets. It's stronger now than before although I would have liked to see a little larger hole in the bottom of the crossbar so that I could reach my fingers in to attach with bolts rather than rivets.
Tested it and all seems fine.
Matt in Viet Nam