Sigil won't open on Mac OS X 10.6

Please read http://code.google.com/p/sigil/wiki/ReportingIssues for
information about submitting a good bug report.

What steps will reproduce the problem?
1. Double-click on sigil
2. "You can't open the application Sigil because it is not supported on this 
type of Mac."
3.
...

What is the expected output? What do you see instead?

What version of the product are you using? On what operating system?
Sigil version 0.5.3 on Mac OS X 10.6

Please provide any additional information below. If your source file
(SGF/EPUB/HTML/etc) is required to fully understand the problem, please
attach it to this issue. Read the ReportingIssues wiki page before
submitting!

Original issue reported on code.google.com by StoneMagpie on 28 Feb 2012 at 12:18

Rainie3535 / sigil

Sigil won't open on Mac OS X 10.6 #1293