Never seen that error before. Try doing a minimal install and add the packages afterwards with the pkgadd command? Most of the src packages aren't of any use, apart from the amiga source code. Might be worth checking the md5 checksum of the tape, mine is :
Code:
md5sum amix21-tape.tar
4c487e0ef6cddc7f54029a91f299575b amix21-tape.tar
md5sum amix_2.1.7z
5637778b0e559c66ac5ebbbda909578d amix_2.1.7z
Can't remember which one is the original downloaded from amigaunix.com.