I just got the SL-2 and installed the MCR54. But is there supposed to be a 1/2-inch gap between the them when slid in all the way? I saw a video from SD that showed the same thing with their MCR54, but is seems strange to have that gap, especially since the SL-2 locking mechanism doesn't really seem to 'lock' the receiver in place with the simple rubber pads providing just a friction hold. I wish I could use the screws on the receiver to truly lock it in place and that there was a proper middle part that would allow that. The Wisycom superslot back plate came with a spacer that is not compatible with the SL-2 - the screws are in the wrong spot and the edge pushes up against the antenna cables. Anyone else seeing this?