I just installed mine... it did not made that "clipping" sound and it could easilly detach from Alice... So I removed the whole mobo, placed it into possition, put a THICK towel on it and hammered it a little with the back of a screwdriver... LOL
not it won't move and works great! No matter how much I pressed it with my fingers, it would not fit properly... I have seen the same with fastatas, idefix expresses and dce scandoublers, depends on the mobo and the expansions once installed whether it will just snap on...