upgraded rednotebook and preview don't show in the pane but in browser

Hello,
I've just upgraded RedNoteBook to the last version , with the windows binaries, and now i can't show preview in the pane, just in the browser. Ether I can't switch with Button edit/preview. As I understood, since 2.1 version, webkit is optional (but highly recommended). If missing, show preview in external browser. So I re-run the installer and didn't see anything like a "webkit" option. I concluded that I have to install separatedly webkit on my python distrib.
After googling, I tried to install webkit and pygtk (all-in-one package) but preview don't show up. Perhaps this is because my Python distrib is 2.7 and not 3, or maybe some path to webkit is nedded. Please, can you tell me if I'm on the right way, or give me the right procedure. I love RedNoteBook and use it everyday since two years to track all my tasks in my job, but i don't like at all previews in a browser, and just because of that, I would not want to use it any more because of that.
Thanx
Frédéric Bevia