I know lots of people have had no problems. I had to have these mounted and framed for entry in a show (first and only one I'd done until two years ago, about to have one print in a show this weekend...) and I just took them to a frame shop in the mall. I don't exactly how they did it or what materials they used. I do recall something about low heat for RC. They are 8x10 mounted on 11x14 boards and framed 11x14. I'll take some closeups when I get a chance.
My point isn't to trash RC paper at all. I'd just like to figure out what's happening to these two. Fortunately (I'm pretty sure) I still have those negatives and could reprint them. In fact I think that would be a cool little project, to see if I could do better today. Both are 35mm. One is on XP2 or XP1 or whatever the version was then. The other I don't remember, except that with the grain I'm reasonably sure it isn't Tri-X. Could be Plus-X. I'll have to dig out the negative.