Perhaps the problem is that I'm running on Mac OS X...
Anyone with experience or hints here?
What are you using for your registry entries? On OS X the "open"
command may come in handy. The following commands will open a site in
your default browser, Safari and Firefox, respectively:
open http://example.com
open -a Safari http://example.com
open -a Firefox http://example.com
On OS X the full path to an app's executable is a bit odd, and you may
need to do further trickery to the passed URL. For Safari, the
executable is in:
/Applications/Safari.app/Contents/MacOS/Safari
Using the open command is probably the best bet on a Mac, but the
executable may be helpful. You could also wrap browser startup in a
shell script, throw that in your path and it would probably work as
expected.