Okay, got this to finally work off of original, backup dvd and HD. Here's what I did so far.
Copied all of my TDATA & UDATA files to my pc HD. Then deleted all of these from xbox HD, so all that I had left on my xbox HD was empty TDATA & UDATA folders.
Now this game plays and loads just fine.
I haven't yet tried coping these save game folders back to see what happens to try and figure out what file or files could be causing this problem with this game.
Any ideas as to what to look for in these folders would be appreciated.
But at least now it is working!!!!