I've been having the same problem, but, like you, have had some success
fixing it. I use "video=atyfb:vmode:13,cmode:8", and it works okay. I get
the noise you refer to when moving windows, but it's tolerable. I hope I can
eventually get the problem fixed altogether, because I'd like to use a higher
resolution (currently, though, anything higher than vmode 13 isn't really
> > Well I have a "workable" linux system on my G3 All-in-one. I have bright
> >video. The video is not shifted (most of time) but!!! Now right off the
> >bat there are verticle "snow". So as the text fills the screen the snow
> >goes with it. First only the top then the whole screen. I have even
> >accidentally had 3 window managers running and they all had the problem.
> >But to varrying degrees (I think). What have I done. I fix two problems
> >and create another.
> I tried upping the bit depth. I am at vmode 13 24 and the first problem
> is gone. Now I get a bit of noise when I move windows around. Other then
> that it is working much better.
> P.S. Not that anyone seems to care