From the Backyardigans episode "Escape from Fairytale Village".
In the US and other international countries, S3E17 is when the Nick Jr. Productions logo (2005) is replaced by the Nickelodeon Lightbulb logo (2008) (there are two versions of this logo, but who cares?; in Canada, that logo did not replace the previous Nick Jr. logo until Season 4). This logo combo can be seen during the rest of Season 3. It wasn't until Season 4 that the Nelvana Limited logo is replaced by another version, as well as the Nickelodeon Lightbulb logo having the copyright notice during the logo. I will upload two versions of the Season 4 TB logo combo: Fullscreen and Widescreen!
This is the Canadian version of it, so the logo combo is reversed, unlike the US version. And both the international and Canadian versions have this version of the end credits, whereas the US has a different version of the end credits.