That's true, derf. And I've done a LOT of drum brakes in my life. I don't mind them so much. I was really happy when brake cleaner hit the market, though. Lots easier and safer to use than compressed air. Just put some newspaper under the wheel and spray them clean! My biggest issue was usually getting the damned keeper back on the pins that hold the shoe in place!

 

I did this same job and had exactly the same problem. I would put it all together with the drum on and a pistonwould pop out. Like you I questioned the wheel cylinders (and in fact replaced them) but this is not the problem. I know that I got it right in the end (after proving that it would do likewise with the new cylinder). But I am not sure what the problem was, except I had my attention called to the bottom "anchor". This is probably where the problem was.
First off, the little edge that keeps the shoe is place is only about 1/4", easy to get it dislocated.
Second, if you look at the shoe it is rounded at the bottom--unlike the secure notch on most shoes. It is also a fact that the "notches" in the cylinder pistons do not exist. Obviously the Saturn engineers were aiming at something that does a ninja twist, facilitated by the curved bottom. It is ballet, not Hank Ford.
What it boils down to is the Saturn rear brakes are a pain to put together. Some guy on youtube uses special jigs to line everything up, which chiefly impressed me with the difficulty of the chore. I did get it together.