These emulators are PORTED to the xbox. This means they were originally wrote for windows (in this case). 1964, PJ64 and UltraHLE are all originally ran under windows. They use a plugin system where you can use different graphics , sounds, or input plugins with the emulator.
Rice makes a Graphics plugin. This is the best opensource plugin availible, and the only one used in Surreal (other than UltraHLE, which does not use a plugin system).
Rice's latest plugin (for WINDOWs mind you) is 5.3.1. It fixes alot of issues, specifically the one mentioned above. You can see yourself by downloading 1964, and selecting rice's plugin and playing the game.
However until the sources are ported to the xbox, and compiled into the surreal xbe's, you will not be able to use it.