The following applies only to users running MacOS X 10.9 (Mavericks):
JPEG previews are not available from Raw Right Away under 10.9.
When you press spacebar to preview a JPEG image, Finder will invoke
the default viewer. However, Raw Right Away will be invoked for NEF,
CR2 and ARW raw file previews.
Changes made in the Preferences dialog may have no effect under 10.9.
Users are asked to use numeric code options instead. See the "Options"
section of the Raw Right Away website for more information about option codes.
Both issues are due to limitations of the 10.9 Quick Look environment.
Note that all Raw Right Away program features are available under 10.10
(Yosemite) and later.