samba share for linux, permissions problem

setting up a samba server and trying to build a share to be used by linux. i can’t seem to get a share built where cp -p won’t issue the “preserving permissions for … denied” message. the plan is for the clients to have the share mounted system wide and all users to have r/w on the share. my smb.conf is not much (partial):

security = user
path = /storage
valid users = nas3 lab
force user = engr
force group = users
read only = No

the use of masks for a linux share don’t seem to be needed, but maybe i’m not fully understanding something.
any suggestions? (suse 11.3 x64.)