Bob took his computer with him, and he downloaded the first day's pictures that night. (He forgot his plug adapter, and the in room high-speed internet was only on their internet TV thingy - not a good idea, BTW - so we used it for little else.)
When we got home he went to download Saturday's pictures, and though the computer showed 150 files, 20 of them were pictured from Friday that he'd deleted, 1 of them was a picture from Sat morning, and the rest were unloadable. He tried - I tried - they wouldn't show up as pictures.
Yikes!! He was about to be sick. Finally he got a recovery program and it recovered the pictures, and he could see thumbnails, but in order to save or work with them he'd have to pay 25GBP for the full version. SO I did a search for free file recovery and got one. It wouldn't download on Bob's computer. Anyway, we let it run for an hour or more (while I slept on the living room floor), and it recovered over 200 files, including some pictures from Sea World last summer! At last, the pictures were usable. What a relief.
We think it was the memory card getting old, and not being formatted lately.
Anyway, just had to add that.