The company that I work for uses Cisco IronPort between the employees and the internet. This requires us to authenticate with our LDAP credentials to hit any site on the internet. Occassionally it decides that we've been idle and re-prompts for authentication.
I am using a MAC running firefox 32.
When I've entered a partial answer into a stack exchange site and then go idle, I will get a popup saying that my browser is being redirected with a options to ok/cancel. Neither option works and it goes into an endless loop making that browser window useless.
To recover from the problem, I have to open a different browser (in my case I open safari) and navigate to an internet site and enter my LDAP credentials to get Ironport to realize I am authorized. I can then switch back to my original browser window and hit OK and everything works correctly.
Based on what I see in the Firebug net Window, it's getting a 307 Proxy Redirect response which causes that popup window. I just got that when asking this question, but just hitting cancel to that didn't immediately pop it up. I will have firebug active the next time I answer a question to see what is causing a looping response.
This is the popup I am talking about:
Pressing Cancel on this immediately pops back up the same dialog because the answer dialog resubmits the same request again.
This is what firebug is showing:
The 200 OK comes after I navigated to a page in another browser. It's like it's immediately retrying when it gets that 307 Proxy Redirect (and tries in a tight loop)