I actually found 2 import CDs for the 2003 Astro Boy series when looking for the soundtrack of the movie on Amazon.com.
Though I would not buy the first CD listed below based on the review and the high price, but I may buy the second listed below.
http://www.amazon.com/Astro-Boy-Original-Sound-Track/dp/B00008DYZT/ref=sr_1_3?ie=UTF8&s=music&qid=1260767884&sr=1-3
There is one review for this (Astro Boy: Original Sound Track Score) CD:
"I truly enjoyed the electronic music in the 2004 Astro Boy remake which is why I bought this CD. But none of that was on this CD. Very disappointing.
Also, the musicianship quality of this CD sounds like it was played by a high school band. The brass section has trouble staying together allot, as though they had too much to drink when they performed this, otherwise, what music was presented is fairly convincingly together, not tight though. I can't see how Sony Pictures would have released this under their name? The entire disk is intrumental, which is fine, but where is all the great music I heard in the anime series?"
http://www.amazon.com/Music-Metro-City-Astro-Boy/dp/B0000W3RNA/ref=sr_1_2?ie=UTF8&s=music&qid=1260767884&sr=1-2
There is no review for this (Music from Metro City: Astro Boy V2) CD.