This New York Times article reports the results of a referendum held in Ireland on the so-called Treaty of Lisbon, by which the European Union hoped to accomplish most of the things which would have resulted from the EU constitution which was rejected by the French and Dutch voters. By a modest margin, the Irish voters rejected the treaty and, because the EU now has to do everything by consensus, killed the treaty in the short run.
The EU has always been more popular with European political leaders than it has been with European voters. The obvious lesson in all this: "Eurocrats" in Brussels should put more imagination and energy into being popular with their constituencies.
Britain has been independent for nearly 1000 years, it was last successfully invaded in 1066. We shouldn't be surprised if Britons would not quickly sign away their sovereignty. Much more recently, the Irish fought hard for their independence and may not be ready to give it up.