Can't get XVideo to work on squeeze

[Walter Hurry <walterhurry@lavabit.com>]

I'm having difficulty getting gxine et al to use Xv.

Googling has provided some information, but not a solution.

I'm running Squeeze 64 bit.

walterh@saturn:~$ xvinfo
X-Video Extension version 2.2
screen #0
 no adaptors present
walterh@saturn:~$

I have an ATI video chipset, and xdpyinfo indicates that XVideo is 
supported. Indeed, on the same machine, booting Fedora 15 from another 
partition the results are:

[walterh@mars ~]$ xvinfo
X-Video Extension version 2.2
screen #0
  Adaptor #0: "Radeon Textured Video"
    number of ports: 16
    port base: 63
    operations supported: PutImage 
    supported visuals:
      depth 24, visualID 0x21
    number of attributes: 7
      "XV_VSYNC" (range 0 to 1)
              client settable attribute
              client gettable attribute (current value is 1)
      "XV_BRIGHTNESS" (range -1000 to 1000)
              client settable attribute
              client gettable attribute (current value is 0)
      "XV_CONTRAST" (range -1000 to 1000)
              client settable attribute
              client gettable attribute (current value is 0)
      "XV_SATURATION" (range -1000 to 1000)
              client settable attribute
              client gettable attribute (current value is 0)
      "XV_HUE" (range -1000 to 1000)
              client settable attribute
              client gettable attribute (current value is 0)
      "XV_COLORSPACE" (range 0 to 1)
              client settable attribute
              client gettable attribute (current value is 0)
      "XV_CRTC" (range -1 to 1)
              client settable attribute
              client gettable attribute (current value is -1)
    maximum XvImage size: 8192 x 8192
    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)
[walterh@mars ~]$

So I conclude that my Squeeze installation is missing an X11 driver 
somewhere, but which one?

By the way, I am using the stock "radeon" kernel module in both cases, 
not the proprietary ATI Catalyst driver.

Can anyone provide a pointer please?

Thanks.