Just wanted to add that I have the same issue and am also running Intel HD 4000 Graphics.
I'm running Arch Linux, Xfce 4.10 with Cairo dock 3.1.2.
http://imgur.com/gMmV9ZD
I started Cairo with: cairo-dock -o -i
I do not experience these issues if I use the cairo backend: cairo-dock -c
Thanks
Just wanted to add that I have the same issue and am also running Intel HD 4000 Graphics.
I'm running Arch Linux, Xfce 4.10 with Cairo dock 3.1.2.
http:// imgur.com/ gMmV9ZD
I started Cairo with: cairo-dock -o -i
I do not experience these issues if I use the cairo backend:
cairo-dock -c
Thanks