The BBC have removed the programme data feeds used by get_iplayer, so search and PVR functions for TV and radio no longer work.  There is no programme information to cache, and it was the cache that supported search and PVR functions.  There is no fix available at this time.  You can still download individual programmes via PID or URL.  Podcast searches still work.

http://iplayerhelp.external.bbc.co.uk/tv/feeds

For a short guide to downloading programmes using the PID method, view the TV Download guide.

EDIT: The instructions above are valid for radio downloads too but you can view more in the Radio Download Guide.

UPDATE: get_iplayer v2.94 fixes/works around a lot of these problems introduced by the changes at the BBC.

Check out the release notes for more info.