It's the xecutor mod, with the avalaunch app installed. I will have to wait till I get home to get you more detailed information than that, with like version numbers etc. I was actually given this xbox for free by my uncle and it came that way, with the mod installed, so I don't have much first hand information or experience with it other than just fooling around with it a bit... probably why I'm having so many issues, lol!

What I do know is that I can use the avalaunch app to examine the backup files I rip to my xbox, so maybe I can also edit the hex in there? I'm thinking that the PAL version does have some additional code you need to change to get it to play nice with the mod, because I read online some others were having trouble getting that game running.

If you can help me get this thing running together, that would be amazing! My only other option is buying an NTSC version, which would cost more to send to Taiwan than the game is even worth!

First let's get the game working from the hdd,I'm thinking a bios update should fix the problem.

Probably right there, as GTA SA was quite a late release. This is the first version of the xecutor (I think), and I doubt it was installed much later than 2004/5. I know this is quite lame, but I have no idea how to update the bios... do you want to take this conversation to PM?

Just thought of something else to try.

Clearing the cache on the hdd,give that a try.

Check PMs dude!  
 

2019 update:

The Pound HD cable has a known issue with wavey lines that run over the image and generally muddy up the screen. I mentioned something about this in a post above.

Turns out there is a simple fix to this problem. Basically, all you have to do is take a USB cable and directly power the Pound cable from a USB port on your TV. The problem is caused by the old power supplies inside original Xboxes not giving enough power to run the Pound cable properly, thus distorting the image.

With the cable plugged into its own power, I am now getting a beautifully clean and clear image, so I would suggest anyone who owns the cable to do the same.

This doesn't effect my issue with San Andreas, however, although even that picture is cleaned up substantially.