Version: (using KDE 4.4.1)
Installed from: openSUSE RPMs
since akonadi became mandatory in kde 4.4, kontact freezes up completely after a while.
workaround: run "killall kontact", then manually find all akonadi processes and "kill -QUIT" them, including the mysqld.
...thats why i think its akonadi breaking it.
*** This bug has been marked as a duplicate of bug 219687 ***