I have been searching to see if this theory pops up anywhere and the Google is failing me, or I am a rare person to think this.
Lois Lane was fully aware the whole time that Jason was Superman's son and originally got with Richard White to cover up the fact that she was pregnant with him. More over, fully aware that he has the capability to accidentally do serious damage to things and people, she trains him when stressed out to use an inhaler, one she has laced with minute amount of Kryptonite to suppress his abilities.
1. Lets assume a direct link to Superman II regardless of the fact that the timeline makes almost no sense. Lois knows she loves Superman regardless of whether or not she remembers finding out Clark is superman and sleeping with him. When she realizes she is pregnant, being a rather intelligent person, Lois figures out that she is missing a few days of memory. Not only does this really, really annoy her, he is gone and she can not confront him. "Lois, I'm sorry I left you."
2. I recall a comic timeline from somewhere that a future Lois has Superman's baby, and to prevent the super powerful fetus from totally destroying her, he gives her some sort of pendant made of a Kryptonite that suppresses his ability.
3. After throwing a grand piano up a set of stairs and all the way across the room in a moment of panic, Jason reaches for his inhaler and realizes he feels better without it and tosses it aside. He is young and may not have full awareness of why, but the inhaler has been causing his weaknesses and breathing problems, not solving them.
I have had this idea since the day the movie came out, and never thought to check and see what people think.
I have always loved this movie, regardless of its slight inconsistencies. I like all the little nods to the Donner movies. The smoking on the rooftop, the scanning Lois' purse, other such memories. To be truthful, I could watch until the Plain comes down in the ball park over and over and over and just stop there, but I enjoy all the action scenes and the interplay between Richard, Superman and Lois.