Jizay, if your partitions are unreadable, that's nothing to do with the drive signature. Even without a signature you should still be able to access the partitions in Windows, or in Linux running the hack CD. It is possible that there is a hardware problem with your phatbox or cradle, which is corrupting the partitions.
It's difficult to tell exactly what is going on, because it's not clear what you've done with both 20GB and 40GB drives so far.
You wrote that you reformatted the partitions on your DMS. Was that the original DMS? Were you careful to format using the FAT32 file system? If you formatted in Windows XP default of NTFS, the drive will not work in the phatbox, and I think the hack CD also would not read it. You didn't resize the partitions, did you?
Let's stay focused on the original DMS. Phatnoise is not going to repair it if there is any evidence that you tried to hack it. Can you access it at all in Windows? Can you transfer any files?