If it's just two then the error most probably lies in the template file. The first table should not show referrer information and it should have the heading of Registered users, while the second table is for the anonymous ones.
Donate to UBBDev today to help aid in Operational, Server and Script Maintenance, and Development costs.
Please also see our parent organization VNC Web Services if you're in the need of a new UBB.threads Install or Upgrade, Site/Server Migrations, or Security and Coding Services.