we use AIX 5.1 smbclient version 2.25. Our current cl version is 5.3.
Common problems, esp when getting manually created files:
Getting the end users to set up shares and permissions.
Users moving, renaming, mis-naming and/or deleting files or even directories.
The user dragging and dropping a shortcut in the share instead of the actual file.
There are also some dos/unix differences with case sensitivity, spaces in path names. etc.