I am having a problem setting the group permission bits on a Samba share.

I have a samba workgroup setup called hyperspace:

workgroup = HYPERSPACE

Within this workgroup I have the following share:

[Our Folder]
comment = Our Directory
path = /data/home/ours
guest account = ours
read only = no
create mask = 0760
guest ok = yes
browseable = yes
writable = yes
directory mask = 0770
volume = Our Directory
force create mode = 775
force directory mode = 775

Now, from Computer-A on my home network I am able to drag & drop (or directly create) folders and files in this share and the group permissions get set perfectly fine as I expect them. Computer-A is WindowsXP in the Hyperspace workgroup.

However, from Computer-B (a company provided laptop) I am able to drag & drop (or directly create) folders and files in this share but the group permission DO NOT get set! Computer-B is WindowsXP configured for the company NT domain; it is NOT in the Hyperspace workgroup. If files are sftp'd however, group permissions get set perfectly fine as I expect them.

My question is, how can I get Computer-B to set the group permissions correctly. Is it because it is NOT in the Hyperspace workgroup but is instead configured for the NT Domain at work? Is there a way to compensate for this.

Thanks!
Mike