I am using "simulate new user each iteration set" with "failed event causes step failure" when testing using TruClient and IE10 (VUgen 11.52 patch 1). In the script I made sure cache and cookies are cleared before the usecase actually starts. The problem is that sometimes the scripts runs into an unexpected situation, and it is rather random at what point this happens. When this happens the script step will then fail and the iteration aborts. Next iteration cache and cookies are cleared, but on the server the session remains for 15 more minutes. So when the browser approaches the server again the page presented is how it was left at time of the abort of the previous iteration. The app developer tells me that I should start IE with the -nomerge commandline option to make sure a new session is started on the server.