I have a Foxconn P43AL motherboard and I need to replace my Ram. I currently have 2 x 2GB DDR2-800 PC2-6400 (whatever that means). I think I have a faulty stick and have been advised that I should replace both at the same time to avoid any mismatch. I would like to know what I should replace it with as in what is compatible and good for my board. If possible a link to a good reliable site to purchase.