Problems with DRI (missing /dev/dri/card0)

[Reto Stalder <retstald@ee.ethz.ch>]

Hi there,

I have some problems with DRI. There are the following entries in
/var/log/XFree86.0.log: 

(II) Module shadow: vendor="The XFree86 Project"
        compiled for 4.2.99.2, module version = 1.0.0
        ABI class: XFree86 ANSI C Emulation, version 0.1
(**) RADEON(0): Disabling page flipping
(!!) RADEON(0): For information on using the multimedia capabilities
 of this adapter, please see http://gatos.sf.net.
(II) do I need RAC?  No, I don't.
(II) resource ranges after preInit:
        [0] 0   0       0x90000000 - 0x9000ffff (0x10000) MX[B]
        [1] 0   0       0x98000000 - 0x9fffffff (0x8000000) MX[B]
        [2] -1  0       0xffffffff - 0xffffffff (0x1) MX[B]
        [3] -1  0       0x00000000 - 0x00000000 (0x1) MX[B]
        [4] -1  0       0xf5200000 - 0xf53fffff (0x200000) MX[B]
        [5] -1  0       0x80080000 - 0x80080fff (0x1000) MX[B]
        [6] -1  0       0x80081000 - 0x80081fff (0x1000) MX[B]
        [7] -1  0       0x80000000 - 0x8007ffff (0x80000) MX[B]
        [8] -1  0       0x90020000 - 0x9003ffff (0x20000) MX[B](B)
        [9] -1  0       0x90000000 - 0x9000ffff (0x10000) MX[B](B)
        [10] -1 0       0x98000000 - 0x9fffffff (0x8000000) MX[B](B)
        [11] 0  0       0x000a0000 - 0x000affff (0x10000) MS[B](OprU)
        [12] 0  0       0x000b0000 - 0x000b7fff (0x8000) MS[B](OprU)
        [13] 0  0       0x000b8000 - 0x000bffff (0x8000) MS[B](OprU)
        [14] 0  0       0x00000400 - 0x000004ff (0x100) IX[B]
        [15] -1 0       0x0000ffff - 0x0000ffff (0x1) IX[B]
        [16] -1 0       0x00000000 - 0x00000000 (0x1) IX[B]
        [17] -1 0       0x00000400 - 0x000004ff (0x100) IX[B](B)
        [18] 0  0       0x000003b0 - 0x000003bb (0xc) IS[B](OprU)
        [19] 0  0       0x000003c0 - 0x000003df (0x20) IS[B](OprU)
drmOpenDevice: minor is 0
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is -1, (No such device)
drmOpenDevice: open result is -1, (No such device)
drmOpenDevice: Open failed
drmOpenDevice: minor is 0
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is -1, (No such device)
drmOpenDevice: open result is -1, (No such device)
drmOpenDevice: Open failed
[drm] failed to load kernel module "radeon"
(II) RADEON(0): [drm] drmOpen failed
(EE) RADEON(0): [dri] DRIScreenInit failed.  Disabling DRI.

And a little bit later on:

(EE) RADEON(0): FBIOPAN_DISPLAY: Invalid argument

The directory /dev/dri exists, but there is no card0 device in there.
How can I create it? 
I don't know it this is important too, but I have a
file /etc/modutils/drm which helds the following line: 
pre-install radeon modprobe agpgart

Has anyone a hint how to solve my problem? 

Thanks in advance,
Reto