xsurf_atapi.device only sees atapi devices (CD-ROM etc.)
XsurfIDE adds both, xsurf_atapi.device and scsi.device (or 2nd.scsi.device or 3rd.scsi.device or 4th.scsi.device, whichever is not yet used by other controllers).
To see a harddrive on the X-Surf, you should scan scsi.device. AFAIK HDToolbox searches the 2nd, 3rd etc. variants automatically.
Bye,
Thomas