Re: beryl black windows bug
Ok I 've made some tests... (no XGL)
In the best combination of beryl's advanced options(texture from pixmap, don't use cow, strict binding, indirect rendering) I got to the 37th window to go black, just with konsole 37 windows and nothing else running. The use of COW option freezes my machine when I try to turn the cube so I checked it without turning the cube when on. The only solution for me too was when I switched from Texture From Pixmap to Copy! Then I got a 60+ windows without any problem but the performance dropped dramatically!! With Copy everything worked fine no black bug at all but a lot slower.
Hope I helped a bit now...