The issue with Spain lies is the (private) banks, not government finances. Unlike Greece, where the government needs to get bailed out, in Spain it is the banks that are in trouble.
The banks were in trouble in Ireland, and Ireland stood behind them (which destroyed them). The banks in Iceland were in trouble and Iceland walked away from them. Much less pain in Iceland compared to what Ireland is going through.
Iceland had their own currency though, and from the looks of a graph I googled up they inflated the ISK 100% since before the crisis. Ireland and Spain don't have that option.
