You guys DO realise that there is no "IOS249" (aside from the nintendo one, but that's a stub), right? For anything else, 249 is just a slot to which you can install "a cIOS" to.
To clarify: if the conversation above was about cars, it would be as follows:
person 1: my car makes a funny noise. How do I fix it? It's parked in a large garage.
person 2: that's strange. I have my car also in a large garage, but it doesn't make that noise.
Yeah, I know: things aren't exactly easified because everyone is naming those slots, but that's just the way it is. Anyway...Kirby return to dreamland isn't a problem game, so it should run fine on cIOS d2x r7 base IOS56 (or even install beta 8). Just install that to slot 249 and it should work fine.
Can't say I've heard of this problem before, though (I finished that game about a week ago). This kind of problem could be because of a bad image.