Memory card won't read MY card reader (Macbook Pro)?

Okay, I just got a MacBook Pro and a Nikon D3100 SLR camera, and of course a memory card too. Problem is that my laptop won't read my memory card. (Picture of my memory card - … )

At first I couldn't really understand it, since I've loaded some photos from my sister memory card onto my laptop. (She has a Nikon D3000, but a totally different memory card - picture hers… )
When my sister then tried to put my memory card into her MacBook Pro - SHE could load it, but mine still wouldn't and I've tried on my dads laptop too.

My laptop is the newest in the house, so I don't get it. It can't be my card reader, it can't be the memory card itself - the only thing that pops into my mind is like two magnets resisting each other - like in physics…

Please - is there any camera geeks out there that have tried this, or at least knows a bit about it? I'm usually Really good with technical stuff, but this just doesn't seem logic to me at all!

Added (1). I forgot the pictures - My memory card ()
My sisters ()

The problem here is the memory card doesn't read the card reader. The card reader is supposed to be reading the memory card, you must have done something wrong when you set it up.