scrolling issue

I've seen this on certain ROMs, and wondered what it might be and if I can adjust or tweak something to fix it, (but maybe it's just something you have to live with depending on where the ROM development is at). It's kind of like a wave that goes across the screen. It seems totally random, I haven't been able to predict it, but it happens maybe once every 10 scrolls or something. You can see it in the mp4, near the end of the clip. Any ideas?

https://mega.nz/#!dx0w3AyB!9kpI1ZgyB...eTVeEA9exVmYT4