Hi Seth,
I'm sorry to hear of this.
Have you tried creating a brand new User on the problem Mac to test with?
Hey Chad,
If you'd like to help us document new issues, and the affected Mac User name doesn't have any spaces or characters inserted, feel free to give us a ring at your convenience from the affected machine in order to fully document any new problems.
If you continue to experience failed connections after Mac OS Unattended sessions are normally closed, please confirm the versions and specific OS X in use there so we can try to recreate from our side.