touchpad movement is shuttering and erratic

[eial at cs.bgu.ac.il]

hello.
I'm running gentoo using hal 0.5.12_rc1, hal-info 20090414 with a alps touchpad and xserver 1.6.1.904, when I run a graphic display (kde or e17), the cursor's movement is shuttering and erratic.
here is my fdi file:
<?xml version="1.0" encoding="UTF-8"?>                                      
<deviceinfo version="0.2">                                                  
  <device>                                                                  
    <match key="info.capabilities" contains="input.touchpad">               
      <match key="info.product" contains="ALPS GlidePoint">                 
        <merge key="input.x11_driver" type="string">synaptics</merge>       
        <merge key="input.x11_options.SHMConfig" type="string">true</merge> 
   <!-- Edges -->                                                           
        <merge key="input.x11_options.LeftEdge" type="string">120</merge>   
        <merge key="input.x11_options.RightEdge" type="string">880</merge>  
        <merge key="input.x11_options.TopEdge" type="string">120</merge>    
        <merge key="input.x11_options.BottomEdge" type="string">650</merge> 
   <!-- Scrolling up/down -->                                               
        <merge key="input.x11_options.HorizEdgeScroll" type="string">true</merge>
        <merge key="input.x11_options.VertEdgeScroll" type="string">true</merge> 
        <merge key="input.x11_options.UpDownScrolling" type="string">true</merge>
        <merge key="input.x11_options.LeftRightScrolling" type="string">true</merge>                                                                                  
        <merge key="input.x11_options.UpDownScrollRepeat" type="string">true</merge>
        <merge key="input.x11_options.LeftRightScrollRepeat" type="string">true</merge>
        <merge key="input.x11_options.MinSpeed" type="string">0.7</merge>
        <merge key="input.x11_options.MaxSpeed" type="string">1.3</merge>
        <merge key="input.x11_options.AccelFactor" type="string">0.050</merge>
        <merge key="input.x11_options.EdgeMotionMinSpeed" type="string">5</merge>
        <merge key="input.x11_options.EdgeMotionMaxSpeed" type="string">10</merge>
        <merge key="input.x11_options.HorizScrollDelta" type="string">45</merge>
        <merge key="input.x11_options.VertScrollDelta" type="string">45</merge>
   <!-- Tapping -->
        <merge key="input.x11_options.TapButton1" type="string">1</merge>
        <merge key="input.x11_options.TapButton2" type="string">2</merge>
        <merge key="input.x11_options.TapButton3" type="string">3</merge>
        <merge key="input.x11_options.FastTaps" type="string">1</merge>
<!--        <merge key="input.x11_options.FingerLow" type="string">25</merge>
        <merge key="input.x11_options.FingerHigh" type="string">30</merge> -->
   <!-- Corner clicks -->
        <merge key="input.x11_options.RBCornerButton" type="string">2</merge>
        <merge key="input.x11_options.RTCornerButton" type="string">3</merge>
      </match>
    </match>
  </device>
</deviceinfo>

when I plug a external usb mouse, I see no such issues.
my kernel version is 2.6.29, I've tried with 2.6.30 too, the issue stays the same, also tried with hal versions 0.5.9.1,0.5.11,0.5.11,0.5.11,0.5.12_rc1 the issue remains the same.

how can I fix this?

thanks in advance