Comment 9 for bug 629363

> I don't know about a theme-engine. How would I check?

Does inkscape, installed via MacPorts (command line version, not packaged as app), look the same as when running the packaged version (0.48.0) from sf.net (which uses a custom Clearlooks-based theme)?
If they look the same, do you have a '~/.gtkrc-2.0' file (gtk settings, including themes, for all gtk+ applications)? (Inkscape.app looks for this file, and if it exists, doesn't load the custom theme from inside the application package).