Hmmm, this is going to be difficult. I blipped past the "trainguy611" part of the first post, assumed we were talking about;
City and Country USA,<kuid:-1:100927>
City and Country USA 2,<kuid:-3:10174>
Which are built into TS2010. Further search shows there are zillions of variations on this route, I think the one you mean is;
City and Country USA TS12,<kuid:275587:100095>
For future reference, you can right click on a route in content manager and select "Copy items to clipboard", then switch to the post window on a forum and hit CTRL V to paste the text.
Main problem I have is I no longer have TS12 installed, so I can't download a 3.7 build route to troubleshoot. What you could try is look up the route on the download station, select DOWNLOAD DETAILS, then "Add all dependencies to DL cart" to see if the missing track will download that way.