Everytime you restore your pc, you are wiping the drive before restoring the backup. Each time this happens the drive info changes slightly, so when DesignMaster is installed and it queries your drive to create your machineID it receives different info than it did last time it was installed, so the machineID is different.
The only way I can think of trying to improve on the situation would be to install DM and then use a 3rd party disk imaging tool like
Acronis TrueImage to make a backup of your drive. That way, when you restore your drive from the TrueImage backup you are restoring an exact image of the drive, just as DM expects it to be, so your machineID stays the same.
Not the perfect solution but a way around at least.
Also, if anyone is looking for a perfect backup software, TrueImage is excellent and can bring you back from a complete drive failure or virus infection in minutes. I can't recommend it enough. It's another peice of software that I have used for years and couldn't be without. ;)