Two possible questionable things:

First: Do you really have the destination folder?
Really /home/webos/ ?

Second: Is your USB port still in good condition?
Mine isn't, so i use rsync for copying lots of files or folders to be able to pick up where the connection stalls or breaks.
Example: rsync -P -r --rsh=ssh * user@192.168.2.15:/home/webos/
where the ssh option may not be needed for USB connection, but i wanted to reference to this option for internet usage as well .