Emulator

configuration settings?

All configurations except GC pad are default. I set the path for the ISO.

Try "enable MMU speed hack"
Try with disabled "Enable Dualcore"
I heard there are maybe problem with the "Pal" version,
or do you have "Ntsc" version ?
I found several threads in the forum where they
got the game working and several with the same
issue mentioned above...
Anyway I think 2.1GHz isn´t enough for the game.

If in enable dual core then it really slows down the FPS but it is still the same issue. With dual core enabled i still get no error messages just the start screen. I'm not sure what version i have,Ntsc or PAL. It is possible 2.1GHz is not fast enough but it runs Starcraft 2 on medium grpahics without any difficulty. Could you post links to those other threads with the same problem?

What ? Enabling dualcore mode should give a good speedup, actually...

Did you try to use "enable MMU speed hack" ?

Yeah, but Starcraft 2 needs a lot less CPU power than Dolphin xD
Because Starcraft 2 is designed to run on Windows.
Wii games need Wii hard & software, they aren´t made to run on windows.
Thats why we need Dolphin, it emulates the hadware and translates
the software language into Windows language while gaming.
Emulating/Translating all that Wii stuff to Windows
is like translating a whole novel with a dictionary
from English to german... imaginate how many
time you require to do that ;)
This means you don´t only need a
PC who is as powerfull like a Wii, you need pc
who is as powerfull like Wii+Emulating Wii stuff.
I also have Starcraft 2, I have a dualcore with
3,2Ghz and I´m able to play the game with
Maximum settings but only a couple of games
are running fullspeed on dolphin...

If you can play the game fullspeed with 2.1Ghz I eat a hat ^^

Go to the forum and use the search function...

I'm sorry to sound like a complete idiot but i can't find how to enable MMU speed hack.

Sorry for the inconvenience

Nah, it´s ok not to know where this option is, it´s hidden.
Start dolphin, right click on the game
(in your case Simpsons Hit&Run) and select "Properties".
I read in the forum that one user said this MAYBE helps.
I don´t have the game so it´s just an idea.
By the way the settings you can find there always only
affect the game you made the right click on.

If this doesn´t work, then I can´t help you,
because I dont own the game...