Solved.

[punkonjunk]

So googling about this tends to return stupid music results.

If I use any kind of compression, it shrinks from 600 some MB down to about 50MB or less. It begins loading, but after checking the memory card, it goes to a never-ending loading screen.

If I don't compress at all, it fails to load in the same way.

I used ultra-ISO to rip a .bin file from the actual game disc.

Could that be the problem? I usually just download them, but this game is somewhat hard to find.
EDIT

Solved. Don't know if I can delete my thread myself, though.

[JAKETHESNAKE28]

dont talk about isos. Please its against the rules.

[firedemon727]

Can somebody close this thread?

[punkonjunk]

it's against the rules to talk about ISOs? That's wierd, especially because this is a legally OK problem, instead of piracy related... I wanted to rip my own game (which I succeeded in doing) instead of downloading one online.

Haha, if that's against the rules, sorry, but that doesn't really make sense anyhow. XD

[Shadowblind]

Its just that this kinda talk leads to ISO talk. So there really isn't anyone at fault here.

[JKKDARK]

I Hope DCemu Staff members will allow legal ISO discussion someday..

[JAKETHESNAKE28]

^^ YA RIGHT. Atleast not anytime soon.