I'm swallowing a bitter pill, so bitter I can't even cry although I feel like it. It looks like I've lost all my photos taken in Switzerland (Mt Titlis was the worst tourist trap ever), Vienna (I tried both Demel and Hotel Sachertorte's sachertorte), Venice (the most touristy place of all Europe but so beautiful), Verona (nice little town), Liechtenstein (too small to have anything outstanding), Milan and some of Budapest. I am very upset and unhappy about it, especially since I kept asking the person who transferred the photos to be very sure before deleting any folders. I'm not good at these things and too nervous and made the mistake of trusting it to someone who's careless.
We had bad luck in that a new 16 gig card malfunctioned, forcing us to have to upload photos into a laptop for extra memory space and that's where all the trouble started.
What I've learnt is 1) it's best to use memory cards of smaller capacity so that should the card malfunction or is lost, you limit your loss.
2) if you bring many cards, number them and put all in one box, not many boxes like I did.
3) the best thing to do, if possible, is to bring a hard drive and save or copy all your photos into it, just to be safe.
There's still some hope that I can get some photos out of the malfunctioned card, photos taken by my Hub. That's the fourth thing I learnt: it's good to have a backup photographer.
Fifth, never trust somebody else, do it yourself. that's my bitter lesson.