cb,
The point I was trying to make that there's a big difference between flying through a dense cloud of volcanic ash (like the BA) and flying through wat we have over Europe at the moment.
The following Airbus document doesn't really say much apart from "be careful out there", but it does say :
In service events show that even low concentration of volcanic ash can cause expensive damage.
http://www.airbus.com/fileadmin/medi..._ENV-SEQ06.pdf