TAChart component has undergone substantial changes in Lazarus 0.9.30:

http://wiki.freepascal.org/Lazarus_0.9.30_release_notes#TAChart

I would like to ask TAChart users, especially those who requested features, to test that their features still work in release version ;-)

There are currently two open bug reports against TAChart:

http://bugs.freepascal.org/view.php?id=17182
is a feature request requiring extensive changes,
so I decided to postpone it until after the release.

http://bugs.freepascal.org/view.php?id=17373
is a serious bug which is actually not a TAChart,
but PropEdit/Object Inspector problem, so I am unable to fix it