Ruby 1.8.6-p111 Rails 1.2.6 Windows XP Pro IE 7
Posting this for posterity's sake, and to see if anyone else hit this issue.
I sporadically hit a strange error in IE7 when I hit a submit button on a form within a Rails app.
Further investigation revealed that, when I hit this error, it was never reaching the controller, which I thought was odd. Also, I did NOT see the same behavior in Firefox 2.x (it worked fine). The results I found on Google for that error didn't make much sense in the context of a Rails app.
As best as I can figure it was the result of trying to pass too much data over an http request (I tried both POST and GET). I noticed that when I tried to pass smaller result sets via the form to a controller it worked fine, but when the result set was very large it would choke with this error (or redirect, or whatever you want to call it). The solution, in my case, was to just pass the minimal information necessary and do a second lookup in the controller.
I hope this helps some future googlers. If anyone else any insights on this issue they'd like to share, please do.