I have 8 Latitude d series notebooks.  The touchpads lock up when using Excel.  They will lock up to where you cannot release an area.  The only way out is to use the Windows key to get out of the program-and then reboot.  When we changed the setting on the touchpad to not lock the pad when typing this seemed to stop the problem.  Now these machines have the left button on the touchpad stop working.  One machine doesn't respond, another switches the left button for the right.  These actions happen sporatically. We do not use the standby mode on these computers, but as we are an accounting firm we use Excel for almost everything!  These touchpad problems do not seem to affect any other software