Going by distant memory, you may have to enable xattrs with Samba and they may also be a mount option with ext3. Ext3 can only store 4kbs of xattrs or Extended Attributes per file which are enough for many OS/2 functions, there are better Linux filesystem choices including JFS when it comes to EA/xattr support.
EA DATA. SF are just EAs and Linux doesn't support them on FAT so as stated above, you need to use the native xattrs.