Unless you are using OS 10.7 or later Sigil 0.6.2 will crash. Try pdurrant's compiled version in the thread "Sigil 0.6.2 released" post #8.
Edit: I have to take that back. The official download crashes on my Lion version on my work Mac.
Last edited by dynabook; 12-07-2012 at 04:31 PM.