I'm progressing, slowly, on my new Unitrack layout with guidance received from many on my "Loads of Questions" thread but I'm now realizing my track plan may have been a little too ambitious for a first N scale layout as I am running into a couple of problems. First of all regarding the topic question, the loco is uncoupling from the rest of the cars behind it at the very top of the overpass located at the top center portion of the layout. As you can see, there's a little bit of a hump there that I think I'm going to have to adjust somehow.It's not happening going right to left, only left to right I'm thinking maybe I should have allowed for more room for a flat section of track at the top with no elevation change before the decent begins or maybe I should have not worried so much about keeping to a 2% grade, maybe making it 2 1/2 or even 3% allowing the train to reach the top of the incline sooner. Well, that die is cast so now, what do I do? Also, the new DCC loco I bought (Bachmann EMD SD-45) is stuttering every now and then and it doesn't seem to be restricted to any one area of the track although I'm finding it happens mostly at slow speed. Wiping down the rails helps a little, maybe because there's construction dust? But really, how clean does the track have to be for N scale? On my 3 rail O gauge layout I clean the track once a season (with a Mr. Clean Magic Eraser soaked with 90% alcohol. The eraser ends up black when I'm done.) How fastidious do I need to be? After all, the track is brand new. It's hardly had time to get dirty. I'm also realizing I'm not a foam scenery kind of person as I'm having a hard time visualizing how I'm going to get the topography to look like what I want it to. I think I'm going to switch to Hydrocal or Structolite plaster over cardboard strips and forget about the foam. But that's after I solve the other problems. Lastly, I had a bit of a chore getting the NCE PowerCab working. I thought I'd have to argue with Ebay or the seller I bought it from about returning it but then I finally read somewhere on-line that the connection from the fascia mounted PCB to the track power buss needs to be either first or last, not in the middle! That little fact certainly wasn't in the manual. I was especially aggravated because I broke my personal rule about never reading manuals or instructions and this time I actually did and nowhere was that mentioned. Well, all is well now, at least with that part. Suggestions about the hump and the stuttering would be helpful.