Drag and drop works best for me -- I'm guessing you dragged it to the wrong folder on the 705.

On RidewithGPS:
-Map the ride and save it on the website
-Download the .gpx Track (not Route) to your desktop (the 3rd selection on the Export tab in RideWithGPS)
-Drag the .gpx file to the GPX folder on the 705.

Then on the 705, select:
-Where To:
-Saved Rides:
-Highlight the ride you want
-Navigate

Oh, Mark be DA MAN !

Thanks for the advice. I think I saved it as a Route and not a Track. Plus, I may have put it in the wrong folder as well. I will check it out when I get home this afternoon.