No, its listed on my custom MCV (Soviet MCV clone), so it should'nt be a MCV problem. I got it to work but, I can only have either Yuri or Zeal, but not both. It seems that in order to add a new country, I have to disable one, which is a big problem since I wanted to add three more Allied nations and three more Soviet nations along with Zeal, and I can't seem to figure out the exect problem, and when I have it where I can play as Zeal, I get Yuri and Zeal MCVs. Also, some of my buildings, even though Unsellable=No is on, I Just can't sell them (sorry if I'm being a pain, just tell me to and I'll leave you alone).
Edit: It seems that the name affects whether the team works or not.