First, you cannot just copy the files and burn them on the CD. You must use the create CD from image option, select the .ccd image file, and let the burn process create the CD from the image file. Assuming you did this, you should also burn it at 1x speed, and using a CD-R CD. Don't use a rewriteable CD-RW CD. Did you do these things?
my understanding is that any write process will have small errors... and that portable/cheap CD and DVD drives are less tolerant of these errors. Hence the advice for both CDs and DVD maps to burn at the very lowest speed possible.
An error in a DVD movie is just a minor glitch in a frame, but it can wipe out US 80 in Kansas on the BMW DVD map!