xf86PostMotionEvent caused server aborting

[antilife]

I wrote a x driver, it read some data from serial line, then i parse data and post some events:

xf86PostButtonEvent work well:
//////////////////////////////////////////
if (priv->zzzOldPush != push) {
      int delta;

      delta = push - priv->zzzOldPush;

      if (priv->zzzOldPush != push) {
          xf86PostButtonEvent(device, 1, 1, (delta > 0), 0, 3, x, y, pressure);
   
      }
  }
//////////////////////////////////////////
but xf86PostButtonEvent can not work, it caused server aborting:
/////////////////////////////////////////
if ( (priv->zzzOldX != x) || (priv->zzzOldY != y)) {
    xf86PostMotionEvent(device, 1, 0, 3, x, y, pressure);
}
/////////////////////////////////////////
anybody who can help me? many thanks!!!!!!!!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.x.org/archives/xorg/attachments/20071224/bc88e757/attachment.html>