Sounds like you figured it out on your own pretty quickly. I've ridden in the rain a good bit and never had that happen. New or good condition used coils might be a good thing. Alternately, you could inspect them really closely and try to seal them. I suspect there's a hairline crack somewhere or some similar breach that's allowing condensation inside the body of them. Maybe from heat or age. A couple other users here have figured out some non-XJ coils that work. Search through the site and see what people have done.
The Corbin seat is really nice but really pricey new ($300+). I just got one and love it. Up to that point, I always wore bike shorts on longer rides. I was going to try a Beadrider seat till this Corbin came along.
