Hi Celalettin,
TestComplete handles cookies automatically by default (recorded cookies are replaced with those generated by the server dynamically), so I suppose the problem is more related to the tested application's logic. I'm not sure how your application works, however I suppose here is what happens:
1. When you login to the application for the first time (during recording), the server generates some cookie for your user session.
2. When you stop recording, the cookie is stored in your web browser and in your recorded traffic.
3. If you did not log out after that, your user session remains active in the web application. I've noticed the following part in the server response: "expires=Mon, 17-Jan-2011 14:12:55". So, it looks like your session is supposed to remain active for about a week until you logout.
4. When you play back the recorded test, TestComplete logs in the application with your credentials and gets the same cookie value because your user session is still active in the web application.
So, I recommend that you do the following:
1. Decrease the number of virtual users. Make the test work correctly with a single virtual user and then add just one more virtual user to check how different login information is handled. It will be much easier to debug your tests this way.
2. Try logging out from your application manually and check whether the same cookie is returned from the web server on test playback after that. If my assumption is correct, the server should generate another cookie value for your account after logout.
BTW, you can find more information on cookie handling in the "Managing Cookies" (
http://www.automatedqa.com/support/viewarticle/12629/) help topic.