thos white slices indicate a lack of video memory. opening a Renderer (TTY) you should see an out of videomemory memory message everytime such a slice appears.
probably yesterday you used a different videoresolution? probably another programm (still) is blocking memory on your graphic card.
do you think this method spares memory even if all the slices are dynamic? (as in the timewarp example what i’ve found now in the girlpower examples - too late :) i have made exactly that)
i guess in case of ~200 vertical dynamic stripes i’ts a lot higher…