Some YafaRay help windows are not close under Ubuntu 14.04 x64. Wings3D continue working OK. You can open other 'help windows'. All windows are closed when you close Wings3D.
It is intentional that help windows stays until you hit the close button on them.
Sorry.. I'm not more clear in my exposition: is non closed when you 'pick' on the close button ( over / right corner..).
Im not under Ubuntu now, but i try tonight. Thanks for you fast response.