Can't Upload to server!

The program will not allow me to upload files. I can sometimes upload 1item at a time but can not upload a file. I get:
[19:57:14] 257 "/public_html/learnbyuniversity/ecourses/salesletters" is your current location
[19:57:14] PORT 192,168,15,103,11,70 [19:57:45] An established connection was aborted by the software in your host machine.
[19:57:45] Server closed connection

Can you help