Yesterday after completing a 2.5 hour x-country flight, as I was descending my fuel pressure alarm went off - pressure was fluctuating 2.0-2.5. Rotax continued to run fine. After landing and taxiing back to my hanger, pressure was back to normal. This happened once before about 30 hours ago, similar situation on descent. After the first time, I flushed all of the fuel lines, checked the gascolator, pressure sensor - did not find anything. Could this be considered 'normal'? Alarms going off on downwind are rather annoying !!