nothing of the sort as cards from GCC countries are banned in eastern europe. it mostly has to do with the issuing banks like a qnb or a commercial bank. if ure someone who travels quite a bit, i suggest its better to keep credit/debit cards from international banks that are in doha like the hsbc or the standard chartered.

cards dont work sometimes due to various reasons - the magnetic strip is usually the least common cause where as the local banks network being down is a more common cause.

Another common cause that most people dont know is that credit/debit cards have velocity parameters set up on them i.e if ure going abroad or on a holiday, thats usually the period u tend to spend more - u need to advise ure bank prior to travel that u will be using ure cards more frequently & they can disable the velocity parameter on ure cards.

now whats a velocity parameter?. its a security feature on cards that dont allow you to spend more than a set amount( eg Qrs.5000/-) in one individual transaction.
you could spend more than the set parameter amount as 2 different transactions on the same POS machine in the same store though!!