Just for the record - a quick search in the bug database for "LocalConnection" gives 88 results, about one half of them unresolved. AFAIK there are some issues related to the new security model regarding Macs and LocalConnection, though it's hard to imagine it would crash the browser... It would be very nice of you if you could find the link to the banner, or at least tell the URL of where it was deployed. I've recently posted a bug related to the changes to security model in FP10 and kind of running out of life examples to prove my case :) I think this issue is related, so, please, if you can remember where it was, it would help.
Best. Oleg
