my hardshell case clips were also clipping the top of the droid tighter at the seam. also causing the button to be extra stiff. i used my smallest precision flathead screwdriver to reach into the button groove. it fight right at the mid point and slipped into the droid allowing me to drag it along the lining while doing some mild prying. now my button works with the case on without a problem.
Sent from my DROID4