What items do you have set to display in the sidebar? It almost looks like you skipped the include in the header(is that still how it is done?) But, I think that you need to double check the instructions, because it seems like you are missing an include somewhere.
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.