I’ve recently implemented Horde as a company-wide PIM, and as with any project, it’s had its configuration-oriented teething problems. It was nothing major, but every time anybody added an event, it came up with an error “Error retrieving free/busy information for user@domain: No free/busy URL found for user@domain”. After a bit of searching, I learned that the problem was just that Kronolith needed to be told to look in the correct address book/books. All our addresses are stored in a single company address book, so all that needed doing was to go into Kronolith’s config page in Horde, then select “Address Books”, add the corporate address book to the list, then select any relevant fields in the box at the bottom. Nice and easy!
Note: In order for the free/busy URLs to work at all you have to have configured each user with a free/busy url and an entry in the Turba address book. The URL should be in the format “http://localhost/horde/kronolith/fb.php?u=username“, replacing horde with the location of your horde install, and username with the horde user, who’s account is linked with their Turba entry.