It's happening with others I see: https://support.mozilla.com/en-US/questions/881454

FIXED!

I reverted back to 3.6.23 and all works fine. From everything I can tell; number of problems submitted, breadth of issues, no access to versions 4, 5, 6 (rapid version turnover with no support), and now beta being released for 8, it seems FF is having the user base do all it's alpha/beta testing without consent. Being in product marketing myself, I probably would have lost a significant percentage of my customer base by now. When FF begins to support a new mainstream release, then I'll be interested again.

It looks like it's fixed in the latest beta firmware release: 5.1.0.012 (2011-10-26)

Well that's all well and good, and maybe some ISPs will implement it, but after checking with ours, they responded as expected. They will -not- install a beta release of firmware on the Barracuda server just because something is broken in Firefox. The feature works just fine in all other browsers, so it's not broken at the Barracuda firewall and there is no other compelling reason to install a beta release.

I personally think they have their customers best interests in mind, as installing a beta release could do untold things and really cause chaos. Working in the same industry, I happen to agree.

So this DOES NOT resolve the problem as far as I'm concerned. I have moved on to evaluating other browsers and may migrate all our systems shortly.

Personally, I think this quick-turn process Firefox has moved to does not leave any room for repairing or fixing problems just like this before a major release. And what's with not being able to move back to 6 or 5 or 4? The last release still "supported" is version 3, and it's the only other one you can download.

I can verify it's not fixed in 9.0 either. However, my ISP just today switched to an updated Barracuda Spam and Virus Firewall. It's running production Firmware version 5.1.0.013 and now the boxes display correctly.

Kudos to Barracuda.