sounds like an instalation error i have no problem with it and i am using 3.5a on version 5.47a and it works fine.. did you install UBB IM? that has a lot of bugs you might not want to install that.
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.