update impossible because of more than 2 simultaneous connexion

Linux 3.6.6
Debian Wheezy
Version 1:0.16.6-4
connection type: FTP

When I try to update to a FTP site that manage a connexion limitation,
I have problems during the update about more than two session opened
at the same time.

When I do the same with filezilla, there no such issu setting session
limitation to 2.

Here is a shor of the debug, there is at least 20 files sent out, then
the connexion issue, then a reconnect and this several time:

> TYPE I
< 200 Type set to I
> PORT 192,168,0,10,158,166
< 200 PORT command successful.
> STOR thumb/thb-FR-Saulieu-Saint_Andoche-a80_2005-08-01_0017.jpg
< 150 Opening BINARY mode data connection for
thumb/thb-FR-Saulieu-Saint_Andoche-a80_2005-08-01_0017.jpg
Closing DTP connection...
> STOR thumb/thb-FR-Audrix-Notre_Dame-9046-0015_pt.jpg
ftp: Set socket error (-2): Could not read response line: connection timed out.
PI socket closed: Could not read response line: connection timed out.
Opening socket to port 21
< 421 Vous ne pouvez avoir que 2 connexions simultannees
Command failed.
Opening socket to port 21
< 421 Vous ne pouvez avoir que 2 connexions simultannees
Opening socket to port 21
< 421 Vous ne pouvez avoir que 2 connexions simultannees
Opening socket to port 21
< 421 Vous ne pouvez avoir que 2 connexions simultannees
Opening socket to port 21
< 421 Vous ne pouvez avoir que 2 connexions simultannees
Opening socket to port 21
< 421 Vous ne pouvez avoir que 2 connexions simultannees
Opening socket to port 21
< 421 Vous ne pouvez avoir que 2 connexions simultannees
Opening socket to port 21
< 220 Serveur de mise a jour des pages perso de Free.fr version [Apr
27 2011 11:43:55]
FTP: Sending 'USER rrr':
> USER rrr
> PASS ...
< 230 User rrr logged in.
> TYPE I
< 200 Type set to I
> PORT 192,168,0,10,228,44
< 200 PORT command successful.
> STOR thumb/thb-Avignon-Palais_des_Papes-7631-0002.jpg
< 150 Opening BINARY mode data connection for
thumb/thb-Avignon-Palais_des_Papes-7631-0002.jpg
Closing DTP connection...
< 200 PORT command successful.
> STOR thumb/thb-FR-Paray_le_Monial-Notre_Dame-7315-0018.jpg
ftp: Set socket error (-2): Could not read response line: connection timed out.
PI socket closed: Could not read response line: connection timed out.
Opening socket to port 21
< 421 Vous ne pouvez avoir que 2 connexions simultannees
Command failed.