FXP still broken in 3.0.11.

Hi,

FXP is still broken in 3.0.11, but the problem is different than in
3.0.7-3.0.10. This time, lftp sends PASV one time too much. With this
new bug, FXP works sometimes, but often fails. It's a race condition, 
what exactly happens depends on how fast the site in passive mode 
reacts to the second PASV command.

Look at the following sample when transferring a file:

---> PASV
<--- 227 Entering Passive Mode (213,113,XXX,XXX,200,178)
(ok so far, site opens port 200,178)
---> PASV
(why is this second PASV sent to the site again? It causes
the site to close port 200,178 and open another port)
---> PORT 213,113,XXX,XXX,200,178
(still the old port is sent to the other site, which
was closed due to the second PASV command)
<--- 200 PORT command successful.
---> RETR some-file.bin
<--- 227 Entering Passive Mode (213,113,XXX,XXX,200,179)
(this is apparently the reply to the second, pointless PASV
command, which tells us that the site is now listening on 200,179
and no longer on 200,178)
---> STOR some-file.bin
<--- 425 Can't build data connection: Connection refused.
(of course, since the the other site is no longer listening
on this port!)

PS: Please reply by email, I'm no longer subscribed to lftp-devel (the
actual reason I unsubscribed was that you implemented everything I ever
wanted, and lftp 3.0.6 was perfect for me, so I lost interest in further
development ;)).

bye,
Till