Unlike previous versions of IMP, 4.1+ no longer contains the 'namespace', 'hierarchies', or 'folders' parameters in servers.php. Instead, namespace configuration is automatically detected from the remote server.
Unlike before where you had to manually identify the namespaces you wanted to view (via the 'hierarchies' parameter), now by default ALL namespaces visibile on the remote server will be displayed.
This may startle users of UW-IMAP when they discover that both 1) all files in the home directory may now show up in the folders list and 2) all sorts of namespaces appear (i.e. '#ftp/', '#shared/') that weren't there before.
To disable these extra namespaces and/or restrict UW-IMAP to your mail directories only (rather than your entire home directory), you will need to reconfigure (and then recompile) your imapd daemon. For detailed instructions on how you can change this parameters, please refer to docs/CONFIG in the c-client/imapd distribution.