PLEASE HELP - Transfer suddenly stops

At an unpredictable point after a Session Queue or direct transfer starts, suddenly the transfer rate drops to zero. Sometimes it stays at zero for a minute or so and then the transfer resumes, but more often than not, it stays at zero until the connection goes idle and I have to restart the transfer. (I tried using the Global Queue function, but when I start the transfer, status goes immediately to "Waiting to Retry" for some reason.) I'm connected via DSL, and I've set SmartFTP as the server admin instructed: Max Retries at -1, Retry Delay at 300, Server Time-Out to 120, Keep Alive disabled, everything else default. And it's not just this particular server; I've tried downloading from others with the same problem resulting.

Here's the log from one such frustrating session. What other information do you need?

Resolving host name 24.243.59.133...
Connecting to (24.243.59.133) -> IP: 24.243.59.133 PORT: 21
Connected to (24.243.59.133) -> Time = 70ms
Socket connected waiting for login sequence.
220 BulletProof FTP Server ready ...
USER gourds
331 Password required for gourds.
PASS (hidden)
230 User gourds logged in.
SYST
215 UNIX Type: L8
FEAT
500 Unknown command.
REST 100
350 REST supported. Ready to resume at byte offset 100.
REST 0
350 REST supported. Ready to resume at byte offset 0.
PWD
257 "/" is current directory.
Cached directory reloaded.
Cached directory reloaded.
Cached directory reloaded.
Cached directory reloaded.
CWD /New Shows/gds12-31-2003.flac/Disc Two
250 CWD command successful. "/New Shows/gds12-31-2003.flac/Disc Two" is current directory.
PWD
257 "/New Shows/gds12-31-2003.flac/Disc Two" is current directory.
Cached directory reloaded.
TYPE I
200 Type set to I.
PASV
500 Unknown command.
PORT 4,12,166,54,4,24
200 Port command successful.
Opening data connection IP: 4.12.166.54 PORT: 1048.
RETR gds12-31-2003d2t09.flac
150 Opening data connection for gds12-31-2003d2t09.flac (45354461 bytes).
Connection closed. Server timeout.
ABOR
426 Cannot retrieve. Failed. Connection reset (10054).
226 ABOR command successful.

When I line up files to download in the Global Queue window and then start the transfer, the message in the Status cell says "Connecting," then "Connected," then immediately "Waiting to Retry"; the download doesn't actually begin ...

Why is it doing that? If I just leave it alone, will it eventually start the transfer?

You can see what's going on by press on the queue item > Show Log.