During my upgrade from Fedora 15 to 16 several things broke, this is nothing new there were alot of major graphical components updated. Those issues were resolved in the week following the F16 release. What I had not expected to break was my network printing setup. In all the years I used Gentoo and upgraded over and over I never had many issues and when I did it was usually my fault.
This time nothing much was apparent aside from printing not working on either the host or client machines. First point of failure was the lack of a running CUPS service on each machine. Ok, so it was stopped during the upgrade and not restarted, annoying but not the end of the world. Still no joy. In the end I found I my previously set sharing settings had changed. With all the other changes in config files being highlighted allowing for manual updates this had slipped through the net. Sharing my printer again in the settings and bingo, everything works as before and auto detects. It has only taken a few minutes of fiddling around to fix but it has been finding those few minutes and being in the right mood to fix it. Hopefully the next upgrade will go a little more smoothly.