I managed to use my Chase Sapphire card two days ago to purchase a tix from a manned attendant at Montparnasse. No issues at all and my card is the old variety - it must be swiped.

One thing I haved noted continually on my current trip to France is the number of times merchants have had issues with getting he swipe to take. Tonight it took the restaurant 5 goes to get the card to work. It is not just my card, the friend I am travelling with also has the Sapphire and has had the same issue. I've had occasions where after 2 attempts they will give the card back and say it doesn't work but when I have insisted they persist (in a very nice fashion) it has always eventually gone thru.