Drag & Drop of a folder with 8 media files in it starts to upload, creates the sub-folder, and shows the first file as uploading. Stops incrementing bytes at 50% of the size of file #1.
At this point stopping the transfer does not work & disconnection does not work. The only recourse is to force quit NetDrive3 which leaves the icon for the drive on the desktop. It will not dismount and restarting NetDrive does not give control back.
In order to resolve the problem, NetDrive3 has to be forced to quit a second time, and Finder needed to be relaunched to disconnect the drive.
No caching is enabled and NetDrive3 is set to always get the file listing from the server.
This appears to be an issue that other similar products are having with extremely large Dropbox volumes.
One product, which also can operate in real-time mode, will pop up a warning that the drive connection has been interrupted and prompt to ignore or disconnect the drive. If ignore is chosen the file upload continues and completes successfully. There is also an extremely long delay between the last few bytes of a file uploading and the server returning confirmation that the file is written in its entirety.