The first scare occurred last month on a Bristol to Barcelona flight when a loss in cabin pressure forced an emergency landing in Limoges. 16 people were brought to hospital and there were claims that the oxygen system didn't work properly. The claims were fiercely denied by Ryanair's Michael O'Leary. Full details of the first incident can be found here.
This latest incident could prove very embarassing, and potentially expensive, for the airline. O'Leary admits that the one thing the airline could never recover from is a poor safety record. Following many years with no reported incidents the last two occurrences happening in such close proximity may make passengers wary of the airline. This is a perception that no low fares airline can afford to carry, as it is only as safe as public perception deems it to be.
This last scare must have been bad, apparently Ryanair offered 'free' refreshments to the passengers from the flight when they returned to Dublin airport. What is the world coming to?