Raw HTTP Response shown in browser instead of being rendered

we're facing a weird and seemingly randomly appearing problem where the browser renders the complete, raw HTTP response (to a GET request) including all headers and the compressed content as text instead of just using the contents and rendering it. This happens for whole page loads as well as postbacks as well as page loads inside an iframe; for sure in Firefox 3.6.*, not sure about IE right now.

Our service is an ASP.NET 2.0 web app running on IIS 7.5, on our test machines we regularly have Fiddler running in the background (wondering if this might be part of the pr开发者_如何学运维oblem).

This behaviour occurs very rarely but we have started seeing this problem lately during our tests.

Has anybody encountered this problem before and knows what causes it and maybe even knows what to do about it?

Cheers, Oliver

In a HTTP response, the headers and body are separated by a blank line. That means that if some part of your server side outputs a newline too soon, this will be interpreted as the content beginning.

So I suspect that for some reason, you output a newline too soon. If it is sent a little later, it will be part of the content and you will not notice (e.g. within html). So there's at least random & weird explained.

Do you always see the entire response (i.e. from HTTP/1.1 200 OK), or from a certain header onwards?