gosh it's worth considering. Tks Ferguson for that info....
August peak dates at 20/1 would make it worth it for someone to put down say 20 euros - and get back 400 euros (-plus a refund of tickets which one gets anyway).
Obviously far less of a risk now volcano has subsided- but if one still has a real concern about booking a flight due to the ash thing then a small flutter may be worth it.