Use the sliders in the Extension Request Percent
  Confidence Levels area to specify the importance, for
  play synchronization, of specific X Requests sent by
  your application during script playback.  This feature
  is provided for advanced users of the X Play/Record
  tool.

  When scripts are recorded, the numbers of various X
  Requests seen are recorded in the script file.  These
  may be used during script playback to help synchronize
  the playback.  By default, the script will only
  continue after the same numbers of X Requests are
  detected during playback (or until timeout).  Changing
  the default confidence levels for particular X
  Requests, allows the script to continue after a
  percentage of the expected number of X Requests have
  been satisfied.