I have a Toshiba Satellite C855 with two RAM slots and one 4GB Ram.
I bought a new RAM but it will not fit in slot 2. I took out the old RAM from the slot 1 and put the new one and it fits without a problem. Both the old and the new RAM will not fit in the slot 2 though. I tried with 30 degree angle as well.
I am afraid to push the RAM with a lot of force because I might ruin it.
Here is a photo of my RAM slots with one RAM installed.
EDIT Here is a photo with the RAM place in the socket. I can not push the RAM more "inside".