ATI Radeon 9800 freezes after using X :1

[Erik Steffl <steffl@bigfoot.com>]

  if I run another instance of X the system freezes when I try to switch
back to the first one (completely, does not respond to keyboard, mouse
or network connections). This only happens if I have two monitors (VGA
and DVI). Any ideas what's the problem?

  system:

    debian unstable
    kernel 2.4 21-ac4
    intel D865PERL MB
    ATI Radeon 9800 + ATI Radeon drivers

  additional info:

  I had similar experience with GeForce FX 5600 Ultra card - after I
connected another monitor (to DVI connector) the system would freeze
after switching to another X server.

  possibly related problem: when I switch to text console and back to X
the colors are screwed up (not all of them).

  when I run X :1 there are some error messages about not being able to
initialize DRI (X :0 can initialize DRI without problems, openGL
programs work):

(II) fglrx(0): VisualConfigs initialized
(EE) fglrx(0): Failed to initialize UMM driver.
(EE) fglrx(0): [drm] failed to remove DRM signal handler
(II) fglrx(0): [drm] removed 1 reserved context for kernel
DRIUnlock called when not locked
(II) fglrx(0): [drm] unmapping 8192 bytes of SAREA 0xf8987000 at
0x40028000
(WW) fglrx(0): ***********************************************
(WW) fglrx(0): * DRI initialization failed!                  *
(WW) fglrx(0): * (maybe driver kernel module missing or bad) *
(WW) fglrx(0): * 2D acceleraton available (MMIO)             *
(WW) fglrx(0): * no 3D acceleration available                *
(WW) fglrx(0): ********************************************* *
(II) fglrx(0): FBADPhys: 0xd0000000 FBMappedSize: 0x08000000
(II) fglrx(0): ----------------------------------
(II) fglrx(0): | panel native mode is 1920x1200 |
(II) fglrx(0): ----------------------------------


  TIA

	erik