Could it be that you have the Waypoint Zoom level at a low level, so they won't show up until zoomed to like 100ft? I'm not sure about the Rhino, but my GPS's have a separate zoom level setting just for waypoints. You didn't say whether they just don't show on the map or they don't show under Find all waypoints.
If the waypoint show up normally in Basecamp under internal storage and you can click on them and get the info, the files must be there in the GPS. Did you have any waypoints in the Rhino before you got BaseCamp and they did show up? Can you save a waypoint in the Rhino using Mark Waypoint and have it show up?
Curious, maybe some senior member will chime in.
Wow. Wish you could explain that, might help others in future.
I have heard that sometimes a 'delete GPX files/power off/power on GPS/reload GPX files' can work in circumstances like this, and it worked on the one occasion I experienced with geocaches showing in BC but not on my Etrex 20. I have all my gpx files installed on a sd card, that way if it happens when I'm out I can remove the card, do a power off/power on cycle and then reinstall the card :)
I don't know if this is in the right section and sorry if it ain't. I am pretty new to Basecamp. I have a RINO 650 GPS and it will not show any waypoints but when I plug into laptop using Basecamp all the waypoints show up on the left under internal storage. How do I get them back into GPS or turn waypoints back on in GPS or send back to GPS. Hopefully this makes sense. Thanks for all your help!