<p>Recently an application I wrote started not working on Internet Explorer. There has been no change to the underlying (ruby on rails) code.</p>

<p>In IE 6 or IE 7, I can make one request (HTTP Post) to the app, but when I try to make a 2nd  request, I get an "Operation Aborted" message. Everything works fine in firefox. The HTTP Request and Response headers are exactly the same. The response header for the correct and incorrect results both have the same content-length (about 104k). The correct response has the full content, but the incorrect response has the content cut off after bout 40k. (So about 65k of the response is just gone.)</p>

<p>The even trickier thing is that if I use the IP address instead of the domain name to make the request, everything works great.</p>

<p>This is an apache2 web server.</p>

<p>Any ideas?</p>

You could try to debug the issue using
Fiddler
. It's free HTTP Proxy tool for Internet Explorer.
It lists every detail of the request and response. Maybe you can see the actual cause of that behaviour inspecting the whole HTTP traffic.
Hope this helps!
alt text http://i.msdn.microsoft.com/Bb250446.ie_introfiddler_fig04(en-us,VS.85).gif