If you use some system for long enough, passing through various release upgrades, installing and uninstalling packages - basically living and using - your system might start be bloated with various remnants of dependencies, unneeded packages, dragging back some relicts or even blocking some new deps. Very unpleasant fact.
More...Sat Jan 26 17:57:42 2013Upd.: Sat May 25 10:04:36 2013
While working on jack IPv6 network stack I've trapped onto bizarre getaddrinfo() behaviour - it was returning me address families in wrong order for passive nameless request. It appears people were trapping onto this bug since 2009 (at least that far I found references to this behaviour in mail-lists).
More...Mon Mar 4 00:06:35 2013Upd.: Sat Mar 9 11:05:16 2013