See attached screen dump: "The map set is approxmiately 3.18Gb, but only 29.3Gb is available in the destination. Please select fewer maps and try again."
I've discovered the problem only happens with the whole-of-Europe map from Velomap.org, which gets split into four files when being sent from Basecamp to the GPS (a Garmin 1000) in order to keep the files under the 4Gb FAT32 file size limit. Single country map files (or continents such as Australia-Oceania, which are small enough to be a single file), install without any problem, but I get the error when trying to install just the Europe map on its own.
Edit: The problem turned out to be a corrupted veloeurope.exe install file. I downloaded it again - came down at a different size - installed the 2nd download into Basecamp, and it transferred to the SD card without problem.
