Hmm is it like connection? They gotta have four hearts in their friend thingy (tired, can't recall the name)? Maybe they need to play together more first? That or maybe they are simply two characters that aren't compatable?
I looked into all of that. Entamas don't need to do several interactions to get them to mate. You just hit marry and that's it. That's what I was told. It is like connecting, and they connect fine when playing a game together. So obviously the connection bits of each one are working fine.
EDIT: I did some troubleshooting with Spiffy, and so far she and I are baffled. Characters are dating service card babies, characters are opposite genders, and battery power is fine. I changed them and I still got the connection fail thing when I tried to marry them. Games still work though.
EDIT2: Well I waited, and no one either had the answer or were baffled. So I set the matchmaker on them both and they both had one female each, one of which is going to be a mimitchi
so it's not a total loss. Aw well, if anyone still wants to post the reason why this problem still took place and give me a solution for if I want to try again, please let me know