Was this Marvel related? I think their animation dept did stuff (and they may have done some comics), but it seems that Marvel didn't have anything to do with anything after season 1 or the '06 stuff. I could be wrong, I never really followed the series.
Well color me perplexed. I always thought that was done by Disney.
But in effect it first season was co-produced by Marvel's animation branch with Brentwood Television and Funnies. The other two subsequent seasons were produced by New World Animation.
Their erratic schedule in syndicated television made it hard to keep up but I do remember the show to have good quality animation and fairly good writing.