Obviously we're no help with the CUPS errors, but they may have a
common cause.  You may want to consult the Fedora forums to see if any
IPv6 changes took place recently -- particularly, if something changed
in /etc/hosts.

One of the problems with BSD and BSDUDP is that they don't have any
ACK mechanism, so amandad can send ACK or REP packets back to the
server and never know that the server didn't get them.

Note that the amandad logfile you sent only included sendbackup
invocations, but amcheck should cause amadmin to invoke selfcheck.
The sendbackup invocations seemed to work, too.  So we're not seeing
logfiles that align with one another.

Dustin

-- 
Storage Software Engineer
http://www.zmanda.com