It's not me talking about, its other developer, I only quote what he says and especially point out that its quote.
But the truth is AmigaOS4, MorphOS, and Linux PPC (which is far more popular than AmigaOS4 and MorphOS): do have that problem. So are you mean that SDL ports on amigaos4, morphos, and Linux do wrong things, and only Wii SDL port does not? Roots of issue can be different, and not little-endian modes vs big-endian modes, but we have a problem for sure. Logically that if 3 oses have that bug, and 1 is not, they're something. Maybe you do something in your SDL which original SDLs didn't do, who knows, but if LinuxPPC has the same issue, then its quite a problem. Maybe all SDLs for all PPC oses except Wii need fixing, maybe DOSBox, maybe both, dunno. But as an issue not local to just some obscure oses, but also happens on LinuxPPC, there is a common problem.