xfce on openSUSE 12.2 with all
updates behaves strange: the mouse no longer works reliably.  I'm not
aware of X configuartion changes that I may have made at that time.

If it happens, moving the mouse pointer with the mouse still work, but
click events no longer reach the application: If I click an inactive tab
in FF, it does not activate that tab; clicking any ok button also fails
(no matter whether that's in a gtk or qt application); and 'xev' does
not seem to see an event.  Right and middle clicks are also dead.

Often the Alt-Tab keycombo to switch between
applications is also defunct.

Often I can trigger this behavior, if I dupple-click a word for
selection in my xterm.

If I click something in emacs, I see on the console:

(emacs:3783): Gdk-CRITICAL **: IA__gdk_window_get_events: assertion `GDK_IS_WINDOW (window)' failed
(emacs:3783): GLib-GObject-CRITICAL **: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(emacs:3783): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed

As a temporary workaround it mostly helps to switch to a different
virtual desktop with Control-Alt-Rightarrow and immediately come back
with C-A-Leftarrow.  Or I must enter 'xfwm4 --replace &'...

/usr/sbin/hwinfo --gfxcard
30: PCI 100.0: 0300 VGA compatible controller (VGA)             
  [Created at pci.319]
  Unique ID: VCu0.PF06ujSHk03
  Parent ID: vSkL.e5RgtFs5f74
  SysFS ID: /devices/pci0000:00/0000:00:01.0/0000:01:00.0
  SysFS BusID: 0000:01:00.0
  Hardware Class: graphics card
  Model: "nVidia GeForce 6200 TurboCache(TM)"
  Vendor: pci 0x10de "nVidia Corporation"
  Device: pci 0x0161 "GeForce 6200 TurboCache(TM)"
  SubVendor: pci 0x1462 "Micro-Star International Co., Ltd."
  SubDevice: pci 0x0271 
  Revision: 0xa1
  Driver: "nouveau"
  Driver Modules: "drm"
  Memory Range: 0xd1000000-0xd1ffffff (rw,non-prefetchable)
  Memory Range: 0xc0000000-0xcfffffff (ro,non-prefetchable)
  Memory Range: 0xd0000000-0xd0ffffff (rw,non-prefetchable)
  IRQ: 16 (131960 events)
  I/O Ports: 0x3c0-0x3df (rw)
  Module Alias: "pci:v000010DEd00000161sv00001462sd00000271bc03sc00i00"
  Driver Info #0:
    XFree86 v4 Server Module: nv
  Driver Info #1:
    XFree86 v4 Server Module: nvidia
    3D Support: yes
  Config Status: cfg=no, avail=yes, need=no, active=unknown
  Attached to: #9 (PCI bridge)

Primary display adapter: #30