latest firefox issue 25th may 2015

[pipdane]

I have also just upgraded to firefox 38 and it is unuseable. It was working before the upgrade. It just hangs and freezes for long periods of time ranging from a few seconds up to infinity - usually in steps at the authentication prompt for the corporate proxy. It may have something to do with single-sign-on that has recently been introduced for the proxy to make it easier for people using MS-Windows?
Starting in safe mode from a terminal gives repeated messages:
"could not obtain winbind domain name!"
I have tried changing my machine from fixed IP to DHCP - it made no difference.
I reset firefox and it runs fine for browsing local files if I don't set the proxy.
I am using Centos 6 with everything up to date.
I used yum to remove and reinstall firefox - no diff.
The strange thing is, I have also tried running firefox from virtual machines inside this same machine - both an old centos 6.0 machine which has not been updated and a Centos 7 machine that was updated a few months ago. Firefox works perfectly on both of these virtual machines running in virtualbox using NAT for the network. I get the corporate proxy dialog and can authenticate with no problems...

[Moderator: split this away from a similarly named topic in the CentOS 5 forums. This is for CentOS 6]