Well, I was just about to make a new thread on Smash Bros. and 1964, but I found this one instead.
I have found 3 errors with Smash Bros. in 1964. I have checked against Mupen and Project64 to make sure. I am running with 32-bit off, I checked.
1) The ready, set, go lights at the start of each level are not correct. They do various things, but not the right thing.

Disabling FPU Hack fixes this, but causes camera problems, at least at the start of Hyrule Castle.
2) As shown here, the Race to the Finish level (1P, all characters) has camera problems. There are three ways this problem manifests itself: By not moving at all, by randomly moving towards some point far off to the edge of the screen, and by not showing anything at all.
3) The credits don't show up at the end of a 1P game.