Ok, so I burnt a copy of my PAL Red Steel game. I'd patched the .iso with the ISOPatcher and set it to "249", but it refused to boot in the Gamma Loader and instead just showed a "Licensed by Nintendo" logo and then after a few seconds reset the console.
I put in the Red Steel disk (The one which I'd dumped my .iso from) to make sure it was ok and that there wasn't anything wrong with the disk.
The game played fine.
I then removed the real game and put the back-up back into the console.
After messing about in the Gamma options for ages trying to make it work, I eventually did from the normal Wii Disk Loader channel, but I wasn't sure what I'd done.
It turns out it was the Red Steel (original) disk being in the machine previously which made it work.
This defeated the point of having a back-up, however.
I then tried the swap-disk method with another original game I had from around that time: Twilight Princess.
Success!
So basically, my backup of Red Steel was refusing to boot, but did when I followed the following steps:
1) Insert Twilight Princess.
2) Let the Wii Menu recognise the disk (So it shows the Twilight Princess logo in the TP window).
3) Load Gamma Back-up Launcher (I did it from the Homebrew Channel).
4) Swap Twilight Princess for my backup which didn't boot normally.
5) Pressed B to return to the Wii Menu.
6) Ran normal Wii Disk Channel.
...And that's all there is to it.
I'm not exactly sure what this means for anyone else, but it might help anyone who's had trouble booting IOS-awkward games.
I put in the Red Steel disk (The one which I'd dumped my .iso from) to make sure it was ok and that there wasn't anything wrong with the disk.
The game played fine.
I then removed the real game and put the back-up back into the console.
After messing about in the Gamma options for ages trying to make it work, I eventually did from the normal Wii Disk Loader channel, but I wasn't sure what I'd done.
It turns out it was the Red Steel (original) disk being in the machine previously which made it work.
This defeated the point of having a back-up, however.
I then tried the swap-disk method with another original game I had from around that time: Twilight Princess.
Success!
So basically, my backup of Red Steel was refusing to boot, but did when I followed the following steps:
1) Insert Twilight Princess.
2) Let the Wii Menu recognise the disk (So it shows the Twilight Princess logo in the TP window).
3) Load Gamma Back-up Launcher (I did it from the Homebrew Channel).
4) Swap Twilight Princess for my backup which didn't boot normally.
5) Pressed B to return to the Wii Menu.
6) Ran normal Wii Disk Channel.
...And that's all there is to it.
I'm not exactly sure what this means for anyone else, but it might help anyone who's had trouble booting IOS-awkward games.