This is an alternate routing that is occasionally enforced upon flights from the Balearic Islands to NW Europe, i.e. the UK.
Due to ATC congestion over South Western France, rather than overflying (roughly!) Barcelona - Toulouse - Nantes - UK etc, the routing is Barcelona - Girona - Avignon - Paris - UK etc.
Hence the extra half hour. This route is also used more often as a 'weekend' ATC routing, again due to congestion.
Hope this helps,
Cheers Dunc
