Found this gem in Recorder.cpp of generals:

  //Kris: Patch 1.01 November 10, 2003 (integrated changes from Matt Campbell)
  // Since we don't seem to have any *visible* desyncs when replaying games, but get this warning
  // virtually every replay, the assumption is our CRC checking is faulty.  Since we're at the
  // tail end of patch season, let's just disable the message, and hope the users believe the
  // problem is fixed. -MDC 3/20/2003
  //TheInGameUI->message("GUI:CRCMismatch");