I don't know why, but for some reason the snap configuration changed on its own . When I move a photo the snap option takes me to the upper left corner of that photo. Also I can’t select and move the guide lines because the snap icon is always active even when I’m not over the guide line.
But I found the solution. Utilities > Options > Mouse > Magnetic Snap Radio (Radii), Change the big number to something like 3 pixels in both boxes. In my case it was on 60473pix and 41575pix.
Now it works fine. I hope that solution helps someone.