Differences between Faule Paula (German)
and other versions of the show:

From Episodes 1 to 23 the show had several differences, mostly the intro, episode title cards, and the credits. These little details were changed in later episode productions, except for the show's title in the intro. The changes were carried over to the international dubs of the show, including the first 23 episodes. There are other minor differences in some episodes as well that I know of, but haven't yet noted 'em down. I will get to them later.

Intro sequence - The beginning part of the tune is a tad bit lower in pitch, and this difference is even present in the French dub. Also, in the scene where Lucy starts thinking of an idea, Lucy makes a "tired" pose of sort before thinking. The trees in this same scene lack the bushy leaves on them, which might possibly suggest the show started production in spring/autumn of 2002/2003. The screen also fades to black a bit during the transition from Lucy laying on the grass field to outside of Lucy's home. Lastly, the title of the show at the beginning zooms out into the background as the latter zooms in, rather than the background being static and just the title zooming in.
Episode Title Card - The background is animated rather than static.
Credits - The background of the credits is different, and isn't animated.

Videos comparing the different scenes below: