xulrunner/firefox won't work with http/ftp (8-STABLE/AMD64)

[Nezmer]

Hi,

I'm not using ports/packages. So you can stop reading here If you don't
care about *unofficial* setups. I also use upstream GCC/binutils to
build stuff.

I'm having a weird issue with firefox and other xulrunner-based apps.
"about:" pages and file:// links would work normally. But http:// or
ftp:// wouldn't.

I would see the link in the address bar but that's it. If I search or
write addresses manually or try to go to a page from the default BBC CSS
feed (which is working), nothing will happen. No progress or connection
errors or crashes.

"firefox --g-fatal-warnings" will not spit a single warning to stdout or
stderror.

Has anyone seen anything like this?
How would I even debug this?

Thank you in advance.