Lets clarify a few things
I can access a Samba share via a networked client (windows/linux etc)
Are you using Nautalus, Konqueror, WIndows host? HOw are you able to access and with what user?
/..same account when logged in via SSH...
Check your 'unix' account and see if the correlation is built between it an Samba and that that user is in a group allowed access. Odds are this is where the issue lies.
1) Check what users are allowed to the share as defined in /etc/samba/smb.conf
comment = Home Directories
browseable = no
read only = no
valid users = joe bob jane
2) Check what user relationships are defined between 'unix' and 'samba'
[root@wizej samba]# cat /etc/samba/smbusers
# Unix_name = SMB_name1 SMB_name2 ...
root = administrator admin
nobody = guest pcguest smbguest
test = TEST
3) As for the use of ACLs in Linux. They do not correlate to the permission which samba uses like you would expect if you were a Windows Admin. I have never personally used Linux ACLs on a box as 99% of file permissions are sufficient with basic unix file perms. Your ability to access the files (please define 'access',,.....read, write, view ect) in on tool and not another is likly as you stated, something crucial, but also likly something simple.