mouse gets stuck on second screen

[David Bridgham]

I run a Debian system with two Radeon HD 2600 Pro video cards, each
with two monitors.  Until a few months ago this was working fine.
Then an update came in and Xorg started segfaulting on startup.  I
found that if I arranged the two monitors on a given card horizontally
instead of vertically, it stopped segfaulting but now had a new
problem.  If I move the mouse cursor to the screen defined by the
second video card, it can never come back to the first.  It gets stuck
over there.

It seems this must be something simple in my config file but I can not
figure it out.  Any suggestions?  Thanks.

 -Dave

Section "ServerLayout"
	Identifier     "X.org Configured"
#	Screen      0  "Screen0" 0 0
#	Screen      1  "Screen1" Above "Screen0"
	Screen      0  "Screen0" 
	Screen      1  "Screen1" Below "Screen0"
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "ServerFlags"
#	Option	"Xinerama" "true"
# 	Option	"DontZap"  "false"
EndSection

Section "Files"
	ModulePath   "/usr/lib/xorg/modules"
	FontPath     "/usr/share/fonts/X11/misc"
	FontPath     "/usr/share/fonts/X11/cyrillic"
	FontPath     "/usr/share/fonts/X11/100dpi/:unscaled"
	FontPath     "/usr/share/fonts/X11/75dpi/:unscaled"
	FontPath     "/usr/share/fonts/X11/Type1"
	FontPath     "/usr/share/fonts/X11/100dpi"
	FontPath     "/usr/share/fonts/X11/75dpi"
	FontPath     "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
	FontPath     "built-ins"
EndSection

Section "Module"
	Load  "dbe"
	Load  "dri2"
	Load  "extmod"
	Load  "glx"
	Load  "record"
	Load  "dri"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "auto"
	Option	    "Device" "/dev/input/mice"
	Option	    "ZAxisMapping" "4 5 6 7"
EndSection

Section "Monitor"
	Identifier	"LL"
EndSection

Section "Monitor"
	Identifier	"LR"
	Option		"RightOf" "LL"
EndSection

Section "Monitor"
	Identifier	"UL"
EndSection

Section "Monitor"
	Identifier	"UR"
	Option		"Rightof" "UL"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz"
        ### [arg]: arg optional
        #Option     "NoAccel"            	# [<bool>]
        #Option     "AccelMethod"        	# [<str>]
        #Option     "offscreensize"      	# [<str>]
        #Option     "SWcursor"           	# [<bool>]
        #Option     "ignoreconnector"    	# [<str>]
        #Option     "forcereduced"       	# [<bool>]
        #Option     "forcedpi"           	# <i>
        #Option     "useconfiguredmonitor" 	# [<bool>]
        #Option     "HPD"                	# <str>
        #Option     "NoRandr"            	# [<bool>]
        #Option     "RROutputOrder"      	# [<str>]
        #Option     "DRI"                	# [<bool>]
        #Option     "TVMode"             	# [<str>]
        #Option     "ScaleType"          	# [<str>]
        #Option     "UseAtomBIOS"        	# [<bool>]
        #Option     "AtomBIOS"           	# [<str>]
        #Option     "UnverifiedFeatures" 	# [<bool>]
        #Option     "Audio"              	# [<bool>]
        #Option     "AudioStreamSilence" 	# [<str>]
        #Option     "HDMI"               	# [<str>]
        #Option     "COHERENT"           	# [<str>]
        #Option     "ForceLowPowerMode"  	# [<bool>]
        #Option     "LowPowerModeEngineClock" 	# <i>
	Identifier  "Card0"
	Driver      "radeonhd"
	VendorName  "ATI Technologies Inc"
	BoardName   "RV630 [Radeon HD 2600 Series]"
	BusID       "PCI:1:0:0"
	Option		"monitor-DVI-I_1/digital" "LR"
	Option		"monitor-DVI-I_2/digital" "LL"
#	Option     "AccelMethod"        	"xaa"
	Option     "AccelMethod"        	"exa"
	Option		"DRI" "on"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz"
        ### [arg]: arg optional
        #Option     "NoAccel"            	# [<bool>]
        #Option     "AccelMethod"        	# [<str>]
        #Option     "offscreensize"      	# [<str>]
        #Option     "SWcursor"           	# [<bool>]
        #Option     "ignoreconnector"    	# [<str>]
        #Option     "forcereduced"       	# [<bool>]
        #Option     "forcedpi"           	# <i>
        #Option     "useconfiguredmonitor" 	# [<bool>]
        #Option     "HPD"                	# <str>
        #Option     "NoRandr"            	# [<bool>]
        #Option     "RROutputOrder"      	# [<str>]
        #Option     "DRI"                	# [<bool>]
        #Option     "TVMode"             	# [<str>]
        #Option     "ScaleType"          	# [<str>]
        #Option     "UseAtomBIOS"        	# [<bool>]
        #Option     "AtomBIOS"           	# [<str>]
        #Option     "UnverifiedFeatures" 	# [<bool>]
        #Option     "Audio"              	# [<bool>]
        #Option     "AudioStreamSilence" 	# [<str>]
        #Option     "HDMI"               	# [<str>]
        #Option     "COHERENT"           	# [<str>]
        #Option     "ForceLowPowerMode"  	# [<bool>]
        #Option     "LowPowerModeEngineClock" 	# <i>
	Identifier  "Card1"
	Driver      "radeonhd"
	VendorName  "ATI Technologies Inc"
	BoardName   "RV630 [Radeon HD 2600 Series]"
	BusID       "PCI:4:0:0"
	Option	    	"monitor-DVI-I_1/digital" "UR"
	Option		"monitor-DVI-I_2/digital" "UL"
#	Option     "AccelMethod"        	"xaa"
	Option     "AccelMethod"        	"exa"
	Option		"DRI" "on"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Card0"
	Monitor    "LL"
	Monitor    "LR"
	SubSection "Display"
		Viewport   0 0
		Depth     1
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     4
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     8
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     15
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     16
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     24
	EndSubSection
EndSection

Section "Screen"
	Identifier "Screen1"
	Device     "Card1"
	Monitor    "UL"
	Monitor    "UR"
	SubSection "Display"
		Viewport   0 0
		Depth     1
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     4
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     8
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     15
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     16
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     24
	EndSubSection
EndSection