>  When activing the X11 drivers (and yuva-16 bit), every time I try to add an effect (i.e. Color 3 Way), I get a crash. I append the dump.

Probably some under- or over-read by those sampling routines ..

I'll look into it, but I guess we better to keep it off main repo
then, I'll play with it more on desktop, and may be fix crashes.