I have that little shit Samsung Galaxy Y. And MX player to play .avi files. I downloaded 2 Sherlock episodes on my computer and copied them to Samsung's SD card. Later I watched one and a little bit of the second one. And when I wanted to continue watching it, they were gone. I checked again from computer and decided to put them in it again. And the same thing happened.
I have 16 G so that's not the problem.
Do I have to put it in some folder and not just in the SD card. But that would be stupid, I already have a bunch of pictures on it and they're not deleting itself.

Does anyone have a similar problem? Or knows what to do?