chrooted users: how to see directory content ?

Hi all.
When I put a user into a guest group (which is the only way you can 
force him to be chrooted, if I'm not wrong), he cannot see his directory 
content (i.e.: the server doesn't respond on a LIST command). He can 
upload/download files (if he knows filenames), but he cannot see them.

Where am I wrong ?!?

Thanks
Aldo