The Lisa has counters for door gasket, air filter and the service kit.  A message is displayed to remind the user of replacement.  Whenever you replace these parts, you should also reset the counters.  The gasket should be replaced every 1,000 cycles, the filter every 400 and service performed every 4,000 cycles.
Press the M icon in the lower right corner.  Use the up/down arrows to navigate to MAINTENANCE and press the icon in the lower left corner.  Use the up/down arrows to navigate to either FILTER, DOOR GASKET, or SERVICE and press the OK icon in the lower left to reset that counter.