Image recovery with USB boot media loader

Using ABR 11 workstation, and trying to recover an image to the same machine. The image is stored in a NAS device that is part of the AD.
If using ABR under Win 7, ABR can enumerate the various folders in the NAS device as on other servers.
If using the USB ABR loader, it can't enumerate the various NAS folders, while all other shares on various Windows servers in the AD can be enumerated. When we try to enumerate folders on the NAS, it does not ask for authentication, while the first time we ask to access a windows server share it does ask for authentication
NAS is a Buffalo 4Gb Terastation.
Thank you
Nicolas