I forgot to mention the card is a R500. there's only one video adapter. it appears to be a problem with the xvideo portion of the driver not interacting with compiz correctly, because it works fine when compiz is not running.
Code:
$ xvinfo
X-Video Extension version 2.2
screen #0
Adaptor #0: "Radeon Textured Video"
number of ports: 16
port base: 91
operations supported: PutImage
supported visuals:
depth 24, visualID 0x21
no port attributes defined
maximum XvImage size: 4096 x 4096
Number of image formats: 4
id: 0x32595559 (YUY2)
guid: 59555932-0000-0010-8000-00aa00389b71
bits per pixel: 16
number of planes: 1
type: YUV (packed)
id: 0x32315659 (YV12)
guid: 59563132-0000-0010-8000-00aa00389b71
bits per pixel: 12
number of planes: 3
type: YUV (planar)
id: 0x30323449 (I420)
guid: 49343230-0000-0010-8000-00aa00389b71
bits per pixel: 12
number of planes: 3
type: YUV (planar)
id: 0x59565955 (UYVY)
guid: 55595659-0000-0010-8000-00aa00389b71
bits per pixel: 16
number of planes: 1
type: YUV (packed)
xorg.conf:
Code:
Option "DRI"
Option "AccelMethod" "EXA"