It's certainly been the case in Doom & Tea Parties, though explicitly by design. The game that became the solo game came first, and when we added more players to the campaign we decided to split that off into its own game. The party in the group game picked up a rumor that turned out to be about something that happened in the solo game, but otherwise there hasn't been any contact between them. Which is a good thing, as far as I'm concerned. Does an end run around the messy issues of diva-ism that JB talks about in his post.
Still, the Robilar comparison isn't perfect. One of the things that tends to happen, it seems, in a game that where one character gets a lot more running time than they others, is that character gains a lot more power and wealth just through the extra attention.
But that solo game? The one that's been running for over ninety sessions now? More than twice the number that the group game's had? Guess what level that character is. Just GUESS.
I asked Trollsmyth this question a couple of days ago. He got it wrong!