If immediately after log-in into HostBill admin area you're being log-out, it probably means that your server cannot keep session data properly.
It can be caused by various reasons, please check that:
- PHP can write to temp folder (usually /tmp) to store session data
- your /tmp partition is not running out of space
- if you're using Interworx with jails, the session.save_path configuration in php.ini needs to point to directory with write permissions ie: doing chmod -R 333 /session_save_path solves the problem.
- To be sure, try clearing browser cache, using different browser