I just watched my two DVD's with Three Stooges cartoons on them.
I'm pretty sure in all of the episodes (13 of them) whenever Moe or Larry talk to Curly Joe they say both names.
For some reason, I disliked the cartoons when I was younger (probably because Curly wasn't Curly to me), but now re-watching them as an adult I find Curly Joe to be somewhat funny. He isn't my most hated Stooge (Joe Besser continues to hold that title), but I have more respect for his acting as Curly.
Anyone know if all the cartoons will ever be made on DVD? It was a bit sad to see how much Moe and Larry had aged over the years. Why can't some people just be immortal?