Hi, I dunno if you have figured it out yet....but you can still cheat.
From my understanding version 1.1 only corrects a framerate problem (which I never experienced). It also fixes the resolution settings in the options so they actually work when you change them.
I only installed v1.1 because it allows you to set higher resolution for some crisp clean looking graphics and it is definitely ALOT nicer looking at max resolution than the crappy low res v1.0
I noticed something with the saved game files and tried it out.
I've broken it down into steps. If you want to cheat with High res graphics of v1.1 just follow these steps:
1. Play your game in version 1.1 with all the cool high res graphics....then save your game. Remember to set the resolution of your game to the correct one that YOU desire before you save. After you have saved the game, exit out of the game.
2. Go to the "/Program Files/CAPCOM/ONIMUSHA3 PC/save" folder and make a backup of the "SAVE" file inside there. Store it in a safe place as we will use it later.
3.Uninstall Onimusha 3 from your computer.
4. Reinstall the game so that you are back at version 1.0.
5. Now go to the newly installed directory, go to the "/save" folder and replace the "SAVE" file with the one we backed up before.
6. When you open the game. You should be able to see all your saved games from before and play them at your high res settings!!! YEAH!! Since it is v1.0 still, You can now use the Trainers by the ASX guy!! Cool huh?!