[CentOS] firefox and IronPort

A couple of weeks ago, I got an autogenerated email from the mail folks
here, telling me they'd quarantined what they thought was spam. The last
time I got one of these was a month or month and a half ago, and I had no
problem.

This time, however, I get a 500 error. When I pulled up firefox's error
console, and clicked on the link, I got
<servername elided>: server does not support RFC 5746, see CVE-2009-3555

I'm told they're running Cisco's IronPort. It appears the patch came out a
year and a half or so ago. However, I also found a post where someone,
apparently running on Windows, couldn't get to a site they needed to,
either with IE 9 or FF10.somethingorother, until they downgraded.

The support folks report they can get there, from Windows boxes.

I've tried Mozilla's workarounds, in about:config, but no joy. My ff is up
to date, including both patches from last week, and as those were
critical, I'm very loathe to downgrade.

a) Is anyone else seeing this?
b) Any thoughts on whether it's an IronPort issue, or whether it might be
a bug (new or reintroduced) browser problem?


         mark