I have not had time to research this but the samething happened to my dell laptop. I do know it is a windows problem because all the keys function fine before windows loads. Any way the way I fixed it is I did a system restore to a few days before the problerm and all is right and has been since I just don't know what trigered it to start.
I did something on the Toshiba Laptop of mine and now I am locked on the FN key.
So when i type "J" the number 1 appears.
when i type "K" the number 2 appears.
I have to press Fn+shift+J to get the "J"
This pretty much happens to me on all the other keys as well.