The odd thing about asking a machine to "randomly" select anything is that computers simply can't do random. There's always some sort of algorithm behind the scenes doing the choosing. It may seem random to the naked eye, but there's logic behind how it works.

We used to do this experiment when I was in high school where we'd get identical calculators, reset them to the factory condition and run random number generators on both of them. Every time they'd pull the same number sequences.

I'm getting a bit off track, but I've said all of this to say that it's quite possible that JVC's random select algorithm just wasn't that great during that generation--if I'm not mistaken, the KD-G720 is an older model--or was designed around a much smaller storage tech, for example CDs or USB devices that held a few megabytes instead of gigabytes.