Weird ALPS touchpad behavior

[W. Van Snyder]

I searched in vain for the answer to this question in
http://www.x.org/wiki/FAQ and
http://lists.freedesktop.org/archives/xorg/.

I have a Dell Latitude D600, which has an "AlpsPS/2 ALPS DualPoint
TouchPad, according to /etc/sysconfig/hwconf.

I'm running CentOS 5.5 (Final), kernel
vmlinuz-2.6.18-164.15.1.el5.centos.plus
, KDE 3.5.4-25.el5.centos.1 Red Hat
and xorg-x11-server-Xorg-1.1.1-48.76.el5_5.1.

Occasionally when moving the cursor using the touchpad, the cursor flies
off to an irrelevant place and does some irrelevant thing.

Thereafter, X has trouble figuring out which window is on top, and won't
top a new window by clicking on it, including on its title bar, until I
switch workspaces, or switch to a text screen (Alt+Ctrl+F1) and back
(Alt+Ctrl+F7).  It also sometimes forgets who has keyboard focus (I use
click-to-focus, not hover-to-focus).  It also sometimes turns off the
screensaver.  Even with only one window in a workspace, after the cursor
goes flying to never-never land, the various rectangles in the window
(such as buttons) don't work until I switch as above.  So, for example,
reading mail with thunderbird or evolution requires to switch in order
to scroll the list of messages, and then switch to scroll in a message,
and then switch to delete a message or reply to it or forward it....

I have the following in xorg.conf:

Section "ServerLayout"
         Identifier     "Default Layout"
         Screen      0  "Screen0" 0 0
         InputDevice    "Keyboard0" "CoreKeyboard"
         InputDevice    "Synaptics" "CorePointer"
EndSection

Section "InputDevice"
         Identifier  "Keyboard0"
         Driver      "kbd"
         Option      "XkbModel" "pc105"
         Option      "XkbLayout" "us"
         Option      "DontVTSwitch" "false"
EndSection

Section "InputDevice"
         Identifier  "Synaptics"
         Driver      "synaptics"
         Option      "Device" "/dev/input/mice"
         Option      "Protocol" "auto-dev"
         Option      "Emulate3Buttons" "yes"
         Option      "LeftEdge" "120"
         Option      "RightEdge" "830"
         Option      "TopEdge" "120"
         Option      "BottomEdge" "650"
         Option      "FingerLow" "14"
         Option      "FingerHigh" "15"
         Option      "MaxTapMove" "110"
         Option      "VertScrollDelta" "20"
         Option      "HorizScrollDelta" "20"
         Option      "MinSpeed" "0.3"
         Option      "MaxSpeed" "0.75"
EndSection

...

Stuff for display....

I had the same behavior using a vanilla ps/2 "mouse" driver with Option
"Protocol" "IMPS/2".

Any ideas?