It's a bug.... a pretty long-running one.
I got so sick of it I learned how to write my own arrows into my label objects.... that was NOT fun, but was still better than having labels jumping away from their leaders.
Oddly, this only seems to happen whent there's a leader. It does not happen when it's just the label (or a label with its own arrows).
I really have to get around to writing some labels and getting them onto objectsOnline....
Tom Waltz