Well I've been tinkering with this on and off for weeks now and can only come to the conclusion it can't be done in Firefox without 3rd party plugins. Which renders firefox useless for us on the network.
I've put the prefs in every damn prefs file I can find: all.js,user.js,prefs.js,whydontyouflippingwellwork .js and anything else I could think of!
Code:
user_pref("capability.policy.policynames", "localfilelinks");
user_pref("capability.policy.localfilelinks.sites", "http://server");
user_pref("capability.policy.localfilelinks.checkloaduri.enabled", "allAccess"); The links come up correctly and work fine in IE, but do nothing in Firefox. I notice none of the above preferences appear when you look through the list in about:config either.
Good old IE - the faithful old dog stays as our standard browser!