The problem is not the key, but old IntraWeb files remaining on your system. We will describe here the general steps to fix this problem:
Please check the How do I install IntraWeb steps
For C++ Builder users
In general, the installer will create an .obj file to be linked to your project, but if for some reason you can´t find a IWLicenseKey.Obj file, in addition to the steps above, you can add the unit IWLicenceKey.pas to your project.
Note: the same instructions are valid for those who do not have the evaluation mode problem, but are not seeing bug fixes after installing a update.