I can see it with Firefox 41.
If I click on edit on your linked side and also if I move the map to the position, activate locale GPS files and wait for some seconds to load.
Maybe a cache problem of your browser?
I am using Firefox 33.1 under Fedora. I tried it in a different browser (webkit based) and the problem persists.
I can also see the track if I click edit. But the track is not displayed in ID editor when the GPS tracks overlay is selected. I am posting an image to illustrate this.