Ultra Compact Flash Card Problem - STRANGE!

Hi Everyone…  I had a family photo shoot yesterday evening.  I put in one of my several SanDisk CF cards, an Ultra 16 GB that I knew had some items on it but wasn’t full.  I wanted to retain the items already on the card, so I didn’t format.  I want through my entire photoshoot, looking at some of the photos as I took them to check for focus, etc.  When I got home at put my card in my card reader, my MacBook took quite a while to show it in my device list.  When it finally did, the language had changed (I’m not even sure to what).  When I clicked on the card name, it showed two folders (as it normally does) for my original files, and two new folders for the new photos, however not named DCIM and whatever else the otehr folder generally is??  THEN, when I tried to click on the folder with the images, it disappeared.  I ejected it, put it back in, and the folders were there again, but as soon as I click on it, it disappears.  SO, what is going on with my card, and are my images from my new session recoverable??