OK, let me be more specific about what I have done.
I created a series of traces using Google Maps, which I converted to gpx files. Each file represents a section of an audax between controls in order that the number of trackpoints remained within the eTrex limit. I then used Memory Map to save these (plus a route using straight lines between routesheet instructions and marks for the control points) as a single gpx file.
I can download this file to my eTrex, and it then shows me the tracks (as seven separate tracks), the route if I set it to "navigate" and the control points. Perfect. For me, anyway.
The original poster has tried to upload the file, and his device only shows the track from the start to the first info control. Which is in accordance with what is posted above. I rode the route yesterday, and saved a tracklog. This was thus a single gpx track of the entire route. Unfortunately the OP could not get this to load into his 800. As I have no knowledge of the Edge series I have nothing more to try.
But obviously there are lots of Edge users riding audax (probably rather more than eTrex users), and I am anxious that I provide something that is useful for everyone. I placed the gpx files (that is one file with just the seven tracks, one file with the route and one with both) on my Thames Valley Audax site (
www.tinyurl.com/UpperThames12). The tracklog is not there yet - I'll upload it when I get home this evening. I'm hoping there is something simple that we can do via BaseCamp, Mapsource or something else to produce something that Edge users can use.