mmh, yes i'm seeing the same problem. not sure what's going but will take a look and let you know
and yes then the threadedPixelBufferExample should do exatcly what you need. downloading pixels form the video memory to ram can be slow, even using PBOs, they just make it possible to do that asynchronously so the main thread is not blokced meanwhile.
if you are using this for computer vision you might want to check if doing those processes in the cpu is faster than using the gpu and then downloading the pixels to ram again.
