Creo que otra serie francesa también usaba la misma música (pero la serie francesa de Sonic tiene otro opening)
Mira, de la wiki de Sonic Retro:
While most international versions of the show used the theme found in the English-language version, the Italian and French versions of the program had an original theme complete with lyrics. Italian, French. The French version is a rough translation of the Italian version, which was composed by Alessandra Valeri Manera, for the Fininvest (now Mediaset) group, known for replacing openings and ending of most TV shows.
Sonic salía en Telecinco, y eso es Mediaset, no? Pues parece que componían canciones y luego en cada país les ponían letra distinta y usaban en distintas series.