Me myself personally, I usually convert DMS images into ADFs and use Tracktool to plunk em on a disk... Oh, and make sure you're using a REAL DD disk, not an HD disk, not even with tape over the other hole.
...tho your problem is likely due to using a high density disk without covering the hole... WB sees the disk as HD, you're putting a DD image on it... Thus, blank disk. Either way, I HIGHLY recommend using real double density disks for disk images.