[Dovecot] *****SPAM***** Upgrading from rc27 to rc29?

[Francisco Reyes]

After sending a messasge about a problem (The folder 'Inbox' cannot contain 
items. Namespace problems) I found what seems to be a fix in the release for 
rc29.

Besides any potential configuration files, do I need to delete the old index 
files? Any of the dovecot files?

Based on the release notes for rc29 it seems the following will fix the 
problem we are experiencing:

IMAP: LIST "" "" didn't return anything if there didn't exist a
	  namespace with empty prefix. This broke some clients.