Mr. Camel: Stereotyping will not help here, it only offers some insight of your thoughtprocess...
Simonpro: The KLM testflight was conducted from SFC to max Level and back down, to cover all levels. And it fits the profile of a normal short haul flight. Maybe you wouldn't be able to go all the way to FL410, but a "normal" jet should make FL 350 in any case (I said normal, not BAE146!). So passing through the 20's will take about 5 minutes on the way up, and another 5 on the way down. At least in what I fly.
LH reports not even a scratch found on the paint, nothing in the engines on a 40 minute flight MUC - FRA at FL240. According to Spiegelonline not even a Metballoon has been launched so far in Germany and all the predictions are calculations by the Volcanic Ash Center in London, not real meassurements.
I am beginning to think that the problem is overrated!
Nic