Your sound.cmp CRC32 value matches that of the disk version of the game (ie it wasn't changed for the download version), so there is nothing wrong with the file itself.

There is a Divine Divinity Music Extractor (72KB) by BrainBox, though it was designed for the disk version of the game, so you will presumably need to move/copy the file to the expected path under the DD folder. Alternately, the soundtrack (and more) can be downloaded from the composer's website in mp3 format. See DD music.