I have a Nikon coolpix s6300 ,Every time I took some photos ,some photos must be destroyed , It looks like this:

I use a class 4 sony 4 GB memory card . My camera is new . I remove the memory card ,took some photos . When the photo is stored in a camera's memory , none of the photos are destroyed .
whats the problem with my camera? or is it the problem with memory card?