When I was in Spain for 4 months a year ago my BoA ATM card didn't work for a day or two at Barclay's in Madrid. THen later in the week it worked just fine. Rather interestingly the 757 area code number on the back of my card would not accept my collect call from Spain. I have no clue as to whhy it didn't work for those 48 hours.

Whenever I go abroad I make sure to call BoA and have them put notes on all of my accounts so I don't have to worry about my cards locking up on me halfway around the world.