Seeing double

[EojL]

Hello. I'm not new to Dolphin, but this is my first time attempting to play a Wii game on it. The game happens to be Geometry Wars Galaxies.

I'm using the latest version of Dolphin and everything is running smoothly, except for one thing: The graphics are either doubling on top of eachother or cloned to the bottom left.

Examples of what I'm referring to:





I followed this guide in regards to improving performance on the main website and my settings are exactly the same, except for two things: I'm using OpenGL instead of Direct3D9 and I have Audio Throttle enabled.

I have Audio Throttle enabled because the game was running too quickly. I'm using OpenGL instead of Direct3D9 because, despite the doubling, it looks much better than what Direct3D9 produces:





I'm not too bothered by the doubling (not yet, at least) but, because I plan to record myself playing it via this emulator since I have no way of recording myself playing on the console, yet, I'd like it if everything could look as nicely as possible.

Any help would be very much appreciated.

Also, since I have this strong feeling that somebody is going to refer me to the search function, I have to say that I've been searching around Google and various message bards, including this one, for an answer to my problem before finally caving in and registering to ask for help. It's possible that I'm a gigantic moron and am just using the wrong keywords, and I apologize in advance if this is the case.