Just spent ages working round a BaseCamp (Garmin) (bug I presume). Thought I would share it with you and maybe it will help or maybe you have a better way.
The bug: I plotted a route on BaseCamp and downloaded it to my Dakota 10. There was lots of spare memory after the download and the file was clearly visable while it was attached to my PC. But when I detached the Dakota the new route was not available and when I re-attached it BaseCamp declared the downloaded file to be corrupt.
The Solution: After much experimentation I found that any route in BaseCamp with 250 or less waypoints will download fine. Between 250 to 500 waypoints and the end of the route is missing. Over about 500 waypoints and the file is corupted during downloading. This is not a memory problem because I can divide a route of 750 waypoints into 3 routes with 250 waypoints each, and download and display all 3 routes (750 waypoints) similtaniously with no problems. If I use BaseCamp to rejoin these routes the bug re-appears.
So if you want to plan a long windy route on BaseCamp (As you don't know till its too late if you will exceed 250 waypoints) I would advise you to put the route in as a new track (not a new route). This will allow you to (first in case it goes wrong export a copy of the new track) then manipulate it by "click on the track title to select it" then go FILE-NEW-"DIRECT ROUTE FROM SELECTED TRACK". Switch off the "choose the number of points automatically" box and enter the number of points as 250 (or less)(this is maximum number that will transfer in one go). If the resulting Route is too gappy and needs more points then go undo, split the track into two with the divide tool and transfer it as two or more routes.
As an aside (If you just happen to be a Garmin employee) I have been waiting ages for an update to BaseCamp. You need to sort this!
Well I started this morning thinking to quickly add a route to my GPS and one thing led to another - boy I wasted so much time. Just had to tell someone.
Thanks