This was really perplexing. I am trying to install a Galaxy GT520 on my Inspiron 546. So i take of the slot i need in the back-plate and fit the card into the slot. But...the card didn't fit into the back-plate. It's like a millimeter off.... There is a little slot that the back-plate slots go into but it doesn't fit into the slot. It's almost like it needs to be a millimeter longer. Thanks to anyone who helps.