The Greek tax problem mainly resides with the baby-boom generation, who after the colonels regime developed such a deep mistrust of any form of government, that they avoided paying taxes any way they could. I remember our holidays there in the nineties, cash payment in dutch guldens or deutchmarks was the norm, no taxes were ever paid by the Greek apartment owners. And the same group has managed to thwart the establishing of a proper cadastre, which is instrumental in recording property value, and the subsequent taxing of that property.
And running a railway company at a 3 million euro/day loss, with drivers getting double the pay of their German and Dutch colleagues doesn't help either. http://www.nytimes.com/2010/07/21/business/global/21rail.html?_r=1
I also remember an article stating that the Greek government has about 70 billion euro's of uncollected taxes on the books. How about they collect that, the northern European countries write off 100 billion, and the Greek government does as it has promised the third time around? That way we can move past this horrid mess with only losers.