I apologize for the delayed response. ArtOfTestRunner.exe should always be run as Administrator and runs Firefox under the default profile. Internet Explorer does not support multiple user profiles running under the same user account.
I take it that you do not see this IE launch issue when executing the tests directly through Test Studio. Can you confirm this? Also, please provide a copy of the same or a similar utility executable and test project that displays this behavior. It might also help to have a clean application log of this behavior. Thanks for providing the information we need to best advise you.
the Telerik team