Description of problem:
Frequently switching X VT / Fast User Switching causes lockup. Processes that
connected to the X server still running but only a blank screen with a cursor
appear at the display. getty VT is also not accessible during the lockup. A look
at the Xorg log theres nothing that says X crashes. gdm-restart through SSH
releases the lockup. 

Version-Release number of selected component (if applicable):
Fedora 6.91 Rawhide

How reproducible:
Frequently

Steps to Reproduce:
1. Login
2. Switch VT .. lots of times

Actual results:
Lockup

Expected results:
Switch VT

Additional info:

My graphic card is i855GM using i810 driver. AIGLX is enabled. 

This is the tail of Xorg.0.log.old

--------------
(II) XINPUT: Adding extended input device "<default pointer>" (type: MOUSE)
(II) XINPUT: Adding extended input device "Keyboard0" (type: KEYBOARD)
(--) <default pointer>: PnP-detected protocol: "ExplorerPS/2"
(II) <default pointer>: ps2EnableDataReporting: succeeded
(II) AIGLX: Suspending AIGLX clients for VT switch
(WW) I810(0): Successfully set original devices
(WW) I810(0): Setting the original video mode instead of restoring
        the saved state
(--) I810(0): A non-CRT device is attached to pipe B.
        No refresh rate overrides will be attempted.
(WW) I810(0): Extended BIOS function 0x5f05 failed.
(II) I810(0): BIOS call 0x5f05 not supported, setting refresh with VBE 3 method.
(II) I810(0): xf86UnbindGARTMemory: unbind key 7
(II) I810(0): xf86UnbindGARTMemory: unbind key 0
(II) I810(0): xf86UnbindGARTMemory: unbind key 1
(II) I810(0): xf86UnbindGARTMemory: unbind key 3
(II) I810(0): xf86UnbindGARTMemory: unbind key 2
(II) I810(0): xf86UnbindGARTMemory: unbind key 4
(II) I810(0): xf86UnbindGARTMemory: unbind key 5
(II) I810(0): xf86UnbindGARTMemory: unbind key 6
(WW) I810(0): Successfully set original devices (2)
(II) I810(0): [drm] removed 1 reserved context for kernel
(II) I810(0): [drm] unmapping 8192 bytes of SAREA 0xf8c42000 at 0xb7fb4000