Guess I'm not alone.
When using my backup copy, the game gets an error saying, "The game disc cannot be read", whenever the level selected is Venice. I figured that out after a couple of days.
If I'm playing on Team Rush, or Team Conflict, and the level is Venice. My Wii makes skipping noises and boom, error.
It also does it on the regular one-player mode on wifi. I haven't played the game long enough to get to the Venice in the Mission mode.
I was going to try another ISO of it, but I didn't want to waste all my disks. I only have two left, and I already wasted 3 on this game, first one was a PAL version, which skipped like crazy, the second was a bad burn, then the third is what I have now. I'm not going for a fourth.