[wmx] Resize-thingy-bug

Hi.

	I am a happy and faithful user of wmx, but all the way since wm2 
there has existed one small bug that has annoyed me. It occurs sometimes
after resizing/overlapping one window with another/just moving around,
whatever. What happens is that the small resize-triangle in the lower
right corner of the focused window is not redrawn, but stays "damaged",
beeing partly filled with black color or something similar.

Is this a bug, a feature, something i've misconfigured in Config.h?
If it is a bug, are you aware of it and would it be easy to fix?
It's not easy being a perfectionist. ;) I'd love to see a patch solving this.

Still. Thanks for providing the community with a wm this tasteful.

Sorry for sort of crossposting, but I wanted to be sure you get this.

Cheers, Linus.