Executive Meddling and Out of Order: The season 1 episode "Lucky 13" was held over from airing until August 11, 2004, which marked the 13th anniversary of when Rugrats had premiered. A few season 2 episodes premiered before "Lucky 13".
The Other Darrin: Notably averted. Everybody had the same voice actors as they did at the time on Rugrats (Joe Alaskey and Nancy Cartwright had taken over for David Doyle (dead) and Christine Cavanaugh (retired) already).
Schedule Slip: A year went by between the first two episodes of season four. Another year went by between the second and third episodes of the same season, after which the rest of the series was burned off on a daily basis for three weeks until it was pulled again with three episodes left. Those three were aired nine months later.