QS just sends the URL to the system to open it via the default browser
(assuming you're using the Open URL... action). You can simulate this
from the Terminal command line with the open command, at the prompt
type open a space and then an URL and hit return. The URL should open
in the browser, starting the browser if needed (same as with QS). Does
it behave the same way?
Safari is my default browser but I just tried opening a URL with
firefox using the Open URL with... action and FF started and showed my
URL (amazon) in the only tab in the only window. I'm using FF 3.0.2,
QS B54 on OS X 10.5.5.
Howard