xubuntu: restoring "drive snapshot" image onto removable disk

I have some images created with Drive Snapshot

I now want to restore one of these images onto a removable disk, using my xububtu system. The removable disk is a USB device which appears as a SCSI device e.g. /dev/sdb

Initially I tried the Drive Snapshot Linux client: http://www.drivesnapshot.de/download/snapshot.static

Unfortunately this tool doesn't seem to like removable disks:

$ sudo ./snapshot.static restore /dev/sdb auto backup.sna

/dev/sdb - must be a device file name of a whole disk i.e. /dev/hdb

Are there any other ways of restoring this image, apart from using qemu to run the dos/windows Drive Snapshot executable?