When logging into an iintegra powered ATS, if your cookies are corrupt, you will immediately be logged out of iintegra again.
To remedy this, use your browser controls to delete the cookies for the ATS only.
The ATS uses cookies to track a user and identify them, the cookie forms part of the sites security and the identity details it stores are used to control the level of access to the ATS a user has. If you remove your cookies for the site, they will automatically be created the next time you log in.