Sounds like the seat is too wide and forcing your legs wider apart than they want to go. Comfort seat is probably wider than standard and could make the problem worse? I had a seat re-done by Tony Archer and experienced similar problems with it on the high setting. It was fine on the low setting. The bike had standard footrests. I think the high setting meant my thighs and hips were being forced apart because the distance from pegs to seat was greater.