I have found that if you go to it to quickly after uploading it does this (always has) but it does seem a little slower these days though a few mins is usually all thats need or just refresh your web page F5@
@moo I use the edge 705 for navigation and more data fields the R20 only has 3 and one is always speed, I have this set to metric so I know how many Kmm's I have done, though I know from the 705 as I have it set to warn me every 25Km=15.53miles and laps at 3.11 miles or 5Km so ten laps 50Km or two distance warning beeps, I also know another way by putting in 5Km waypoints on the tcx file I use for a route this then shows the 5Km 10Km ect on the map as I approach it.
I use the data from the R20 for my database since I have been using it since Dec, but I upload the 705 data to rwgps and Strava as it elevation is more accurate ( just trying to get back some that strava nicked off me using the bryton)
On another note
@Stonechat I have only got 7 rides with my avg cad being 90 or greater though I think I had the Edge 500 set to include zeros so there may have been a few more.
No real pattern to it that I can see.