This article illustrates some of the reasons on why Greece is in trouble.
One key aspect is that Greece came out of the colonels' dictatorship in the '70s without changing the taxation system. The very rich basically don't pay taxes, everyone else does.
A somewhat similar scenario rose in Italy, in the same period. Companies, small and big, were allowed to self-regulate their tax declarations, and as a consequence tax evasion became the norm. It was a political gift from the Christian Democrats to their private supporters, basically.
Public servants and state-controlled companies could not do this, and as a consequence they always paid all the taxes. The constant increase in budget deficit started with this non-sensical choice.
Mafia and organized crime in general also should be added to the equation, as they increased in power from the '70s onwards (in fact, Berlusconi "appeared" as a "businessman" in this period). Compare the problem with public deficit in the US.
My guess is that similar scenarios arose in Spain and Portugal, which had Franco and Salazar for decades. I guess that the rich had similar privileges, and subsequent democratic governments never bothered to rectify the situation.
In the meanwhile, the northern european bloc of countries never had problems with democracy, including citizens and companies who don't pay taxes when they should. As far as I know, Finns and finnish companies enjoy a healthy welfare system because they work hard and pay their taxes, all of them, in increasing measures. They have a way to support the system.
So, the countries that have problems now are those countries that had problems with basic democratic issues before, chiefly amongst them taxation. When the EU was formed, these issues WERE NOT taken in consideration by the founding bodies.
As a result of such myopic attitude, nobody acknowledged that sooner or later the DIFFERENCE in social and economic structures amongst countries would have led to a crisis.
One illustrative example is the following: the current Italian government, led by Mario Monti, is increasing tax revenue and imposing (quite) stronger controls on tax evasion. The goal is to squeeze more money from the ones that did not pay before, to level out things. Whether it will work or not is up to debate.
So, movements like "true finns" may even be right in complaining that their quality of life could even be lightly lowered by "lending" money to the "southerners". This is just xenophobic, headless chook propaganda that exists in each european country: Gert Wildeers in NL, Lega Nord in Italy, etc.
The fact is that Europe needs a COMMON fiscal policy, so that everybody pays taxes and can finance a properly working system, without dirty cheats. After that, integrated social policies would also be necessary, but that's already another topic.
Otherwise, talking about "EU" and the "euro" is non-sense, except for having an easier time to buy Daifukkatsu posters and getting drunk in Pamplona.
Maybe the "true finns", or the horders of bloody xenophobic retards pestering the continent, could support these propositions, eh.
"The only desire the Culture could not satisfy from within itself was one common to both the descendants of its original human stock and the machines [...]: the urge not to feel useless."
I.M. Banks, "Consider Phlebas" (1988: 43).