Perhaps this will come off as a bit smug, but sometimes TV shows are too clever and too transcendent--and therefore they are doomed to fail. I think this is the case with "Time Squad". While the basic story idea is basically a reworking of "Mr. Peabody and Sherman" (with Otto looking an awful lot like Sherman), the show had a really smart style and writing that probably baffled audiences. In some ways, much of the humor was lost of kids (such as the jokes and the rather 'special' relationship between Tuddrussel and Larry) and adults, who might have enjoyed the show, avoided it because it was a cartoon. As for me, I showed a few of the episodes to my history classes and the kids loved them--even if the stories were highly suspect historically speaking. But, the show WAS quite funny.
By the way, I have no idea why but the IMDb page for this show is VERY incomplete. It doesn't even list the full cast and most of the episodes aren't even listed or their air dates. Odd. And, it also makes it appear as if the show is STILL on--though it ended in November, 2003.