-- Last Updated: Oct-02-12 9:39 AM EST --
Like any new stability curve in a boat, you will get used to the solo canoe. It just takes time and relaxing. I would suggest that you spend some time paddling with your weight over in the bilge, purposely off center, so the boat is riding towards its gunwales. Once you get used to that angle as a solid position, you'll be more comfortable with the side to side wobble when you are paddling from the center. You'll already know where the boat is going to stop.
It is possible that the boat you have had a seat that was set up for sitting. In that case you should move the seat higher by a notch to make it right for kneeling. But the saddle that folks are talking about would go a long way to increase your comfort.
One little-discussed aspect of comfort for kneeling is the tops of the feet. I find I need double layers of padding there - not only the kneeling pad, but something like full out mukluks that put a layer of padding over my feet and lower legs. It is a hot option in warm weather since my mukluks are actually diving dry boots, but I really need every bit of that thickness. The other issue can be having the tops of the feet stretched out flat - only solution to that is time and getting acclimated though.
Kneeling is a more effective position than sitting, but it is more problematical in terms of comfort. Even with a kneeling pad and knee pads, there is only so long before I have to hit the seat. I don't seem to be alone - just mess with the boat and see what it takes to be comfortable.