I will post this one last time.
This works! I have been Flamed, told it cant work, called a lier but I'm telling you this is what i did this is what two friends of mine did and we are all playing enter the matrix with no problems what the heck try it and see you may be surprised.
I patched enter the matrix with Iso Craxtion V21 and its been playing great using old bios 4973 I'm up to level 4 The sewers and playing as Ghost no problems at all.
Here is how.
First turn all 3 IGR's to No Then:
1. FTP game from the original DVD to the computer HD
2. Save game to Xbox HD
3. Patch default XBE on computer HD with IsoCreaxion V21
4. FTP patched default XBE back to Xbox overwrite game XBE and play away.
This is all i did I'm playing 5 days now don't tell me this wont work or it cant work it is working I'm playing I think I'm going to play some more right now.