upload fails after xxx bytes

I have uploaded many files to this server OK.
But certain files just won't upload.
The upload fails after a certain number of bytes.
The fail point will be different for different files.
But for a given file , it always fails at the same point.
For example if a 3mb file fails after 950k it will continue to fail at 950k.
While another file of 150k might fail after 80k. In which case it will continue to fail at 80k.

If I que the file auto-resume fails repeatedly.

Any ideas?
Here is a log:

200 NOOP command received
TYPE I
200 Type Binary
PASV
227 Listening on (xxxxx)
Opening data connection IP: xxxxx PORT: 1130.
STOR beal2.dat
150 Opening data connection
Connection closed. Server timeout.
Connection closed. Server timeout.
TYPE A
200 Type ASCII
PASV
227 Listening on (xxxxx)
Opening data connection IP: xxxxx PORT: 1131.
LIST -aL
500 File transfer failed
150 Opening data connection
226 Transfer complete

Some additional info:
My ISP is AOL
AOL has crude but useable FTP tools.
I AM able to uload these files to my server with AOL.
I AM NOT able to upload these files with SmartFTP !!