You need to check the filesizes of the disk images. DiskCopy 4.2 images have a header at the start of the file. If you don't strip this, then the images won't write correctly with Rawrite.
If the images are 1,474,644 bytes then you need to strip the header. You can do this in OS X from the terminal:
dd if=disk1.image bs=84 skip=1 of=disk1-trimmed.image
The trimmed disk should be 1,474,560 bytes. You can then write this with Rawrite.
If the images are 1,474,644 bytes then you need to strip the header. You can do this in OS X from the terminal:
dd if=disk1.image bs=84 skip=1 of=disk1-trimmed.image
The trimmed disk should be 1,474,560 bytes. You can then write this with Rawrite.