Works correct on my setup ragnarok + Voodoo, except exit to Workbench.
Many thanks to you Cowcat
XBR works fine on fullscreen, but with scale_factor 3, I'm not satisfice.
I prefer fullscreen on 800x600, set scale_factor 2, without XBR.
Yes, smaller view, but nicer.
For complete happiness, only the centering option of the image on screen is missing.