Skewer animation causes GFX artifacts, window decoration not always drawn

I tried to get a screenshot, but was having difficulty.

That being said, it should be easy to reproduce.

1. enable 'skewer' for minimize in animations (CCSM)

2. set animation to be somewhat slow

3. seems to be more visible at lower 'Window Grid width' and 'Window Grid height' - so adjust them in CCSM under 'animation addons', skewer (section).

4. now start minimizing windows (adjust and play with the settings a little bit).

You should see some artifacts (briefly), window decortion not always being drawn, etc.

Aside from that the animation is really smooth, and seems to work okay - but it is definitely not rendering properly.

(atleast on my machine using Nvidia).