The problems aren't due the fact that our currency union is extended or our 'medieval' banking system (this absolutely isn't true for the Netherlands).
The fact is that due to the economic crisis of 2008 the States in Europe had to Nationalize (is that correct English? -> buy) system banks. Because if they didn't, the economy would collapse. And in Greece there where problems they didn't report. Result of these both combined with the currency link between the countries had as result that we needed to (temporary) save Greece and Ireland.
The European crisis nowadays isn't only Greece, Italy, Spain and Portugal are also in big problems. Ireland is out of problems now. Italy, Spain and Portugal are doing good (yes, they'll need help) (1)