Content of DVD disappears in Finder

I have a Mac Pro (2011) running Mavericks. It's been running flawless.

I received 3 data DVDs (with photos) from one of my friends. Inserted it, the optical drive shows up in Finder (sidebar) but whenever I click on it, I can see the folders of the DVD for a second but then it (I mean the photo folders) disappear immediately, as if the DVD's were blank. Clicking on the drive again the same happens - with all 3 DVD's.

My friend is using Windows, he can see and open the folders without any problem. I had no problem with any other DVDs so far.... Tried with other DVD's and they're working just fine.

I looked in disc utilities, and it sees the dvd is there.