yea, those were a bitch with my 2:100, but a flat head screw driver used as a pry bar and a lot of pinched fingers got them in.
I have in the past used nylon washers on the front and back of the rack screws to isolate, but the problem is the threads can touch the inside of the ear and of course, conduct through to the rails.
edit whoops wrong link
these look like what you need