I'm using Windows Vista x64 with SP1, and developing an ASP.NET app with IIS7 as the web server. I've got a problem where my cookies aren't "sticking" to the session, so I had a google and found that there was a known issue with duplicate response headers overwriting instead of being added to the session. This problem was, however, supposed to have been fixed in Service Pack 1 for Vista.

Any ideas as to what my trouble might be?

Many thanks in advance.

+1  A: 

Just a thought, have you got an underscore in the url. e.g. http://my_site ?

And one other thing, you're not running the app pool in web garden mode? i.e. Process Model -> Maximum Worker Processes: > 1

What type of app pool are you using - Integrated or Classic mode ?

What does the URL have to do with it? I think I am having a problem with this!
Pete...a long time ago in a galaxy far away, I had a problem where if I had a site name with an underscore but not fully qualified DNS, cookie handling broke because the underscore changed the security zone in IE.
Kev it's a dim an distant memory now but always something I check for if cookies start behaving oddly.
I tried changing the app pool's pipeline mode to Classic, which seemed to fix the problem.Thanks very much to Kevin Kenny for your help.
Lucas Richter

Hi Kevin, I'm using an Integrated app pool, and the max number of worker processes == 1.

What's the significance of the underscore? Does it matter where in the URL it is (e.g. it matters if it's in the host name, but not if it's in the query string)?

Lucas Richter