Custom widget in Creators form editor

[Frej]

Hi i have created a Custom Widget plugin wich works fine in Designer and I now want to use it in Qt creator form editor. So I place the plugin in my QtCreator.app/Contents/MacOS/designer folder. When starting up creator and looking in the tools->form editor->About Qt designer plugins my plugin appear along side of the qwebview but I get an error while loading the plugin. Error: Incompatoble Qt library: cannot mix debug and release libraries

As described in the custom widget plugin manual I have the line:
CONFIG += debug_and_release
in my .proj file for my plugin. I have also tried changing and changing the project setting and changing build configuration to release or build. But none of these fixes the problem. Any input?

//
Frej

[Frej]

Nobody has any idea how to get around this?