Completely Different Title: The word "Laputa" was dropped from the title in the Spanish and US releases because it means "the whore" in Spanish. Miyazaki took the name from Gulliver's Travels, likely without even realizing that Jonathan Swift had chosen the name for that very reason. However, most international releases of the film kept the word anyway. It is exclusively called Laputa in Australia.
Dawson Casting: Pazu and Sheeta (both at approximately 13-14; it's never stated in the movie) are voiced in the Disney English version by (fittingly enough) James Van Der Beek (21) and Anna Paquin (17), and sound considerably more mature than their intended ages. Longtime fans of the original Japanese version have stated this as a point of contention, while others don't find it so distracting.
Ironically enough, in the Japanese version, Mayumi Tanaka and Keiko Yokoyama, both who were in their thirties (as were Barbara Goodson and Lara Cody from the dub from the 80s Streamline release, at 38 and 30, respectively), portray Pazu and Sheeta as high-pitched-sounding kids. It remains debatable over whose performance of these two characters are preferable.
No Export for You: Ironically, the soundtrack of the US score is only available for purchase in Japan. The English dub with said soundtrack is admittedly included as a bonus feature on the Japanese Blu-ray, but it's still a bit odd. (The rescore is also on the Australian and UK BD releases.)