Yesterday I spent way too much time trying to chase down a problem for a new web project re-doing http://homeappraisers.com. All my cool state/county selection prototype ajax stuff was working great on my test server in all browsers, and fine on my live server as well, until my client tried it on the live server in IE.
After lots of scratching and crawling for answers, I finally discovered that the culprit was this one setting in my http.conf file.
# KeepAlive: Whether or not to allow persistent connections (more than
# one request per connection). Set to “Off” to deactivate.
#
KeepAlive On
I don’t know who turned it on when we set up that machine, but there ya go.
Turn it off if for some reason it is on on your server. Then be free to Ajax away