I remember when Season 1 aired on PBS during the 1996-97 season, the title card involving the "Superhero D.W." had an announcer say a phrase, and when D.W. lands her feet on the ground, the same announcer said "It's SUPER SISTER!"
But, by the fall of 1997, upon the launch of Season 2, in the U.S., the announcer's voice was eliminated, and the rebroadcasts from Season 1 had those title cards revised to remove "It's Super Sister" removed. Canadian and likely international broadcasts were not affected.
My question is, did the modification occur because DC Comics, the publisher of Superman, filed a lawsuit against Nelvana (who produced Arthur at the time), or at least threatened legal action?