SmartFTP via Cproxy

If I use FTP via Cproxy (SOCKS 4, localhost 9000) I've a problem. The log is here:

[codebox][03:06:49] SmartFTP v2.5.1006.43
[03:06:49] Resolving host name "****"
[03:06:49] Proxy: Resolving host name localhost
[03:06:49] Connecting to **** Port: 21
[03:06:49] Proxy: Connecting to SOCKS4 proxy server localhost Port: 9000
[03:06:49] Proxy: Connected to proxy server. Sending connection request.
[03:06:50] Connected to ****.
[03:06:51] 220 (vsFTPd 2.0.4)
[03:06:51] USER ****
[03:06:51] 331 Please specify the password.
[03:06:51] PASS (hidden)
[03:06:51] 230 Login successful.
[03:06:51] SYST
[03:06:51] 215 UNIX Type: L8
[03:06:51] Detected Server Type: UNIX
[03:06:51] FEAT
[03:06:52] 211-Features:
[03:06:52] EPRT
[03:06:52] EPSV
[03:06:52] MDTM
[03:06:52] PASV
[03:06:52] REST STREAM
[03:06:52] SIZE
[03:06:52] TVFS
[03:06:52] 211 End
[03:06:52] PWD
[03:06:52] 257 "/"
[03:06:52] CWD /dr
[03:06:52] 250 Directory successfully changed.
[03:06:52] PWD
[03:06:53] 257 "/dr"
[03:06:53] TYPE A
[03:06:53] 200 Switching to ASCII mode.
[03:06:53] PASV
[03:06:53] 550 Permission denied.
[03:06:53] Automatic failover of data connection mode from "Active Mode (PORT)" to "Passive Mode (PASV)".
[03:06:53] PASV
[03:06:53] 550 Permission denied.
[/codebox]

If I use direct connection, all is ok:

[codebox][03:08:46] SmartFTP v2.5.1006.43
[03:08:46] Resolving host name "****"
[03:08:46] Connecting to **** Port: 21
[03:08:46] Connected to ****.
[03:08:46] 220 (vsFTPd 2.0.4)
[03:08:46] USER ****
[03:08:46] 331 Please specify the password.
[03:08:46] PASS (hidden)
[03:08:46] 230 Login successful.
[03:08:46] SYST
[03:08:47] 215 UNIX Type: L8
[03:08:47] Detected Server Type: UNIX
[03:08:47] FEAT
[03:08:47] 211-Features:
[03:08:47] EPRT
[03:08:47] EPSV
[03:08:47] MDTM
[03:08:47] PASV
[03:08:47] REST STREAM
[03:08:47] SIZE
[03:08:47] TVFS
[03:08:47] 211 End
[03:08:47] PWD
[03:08:47] 257 "/"
[03:08:47] CWD /dr
[03:08:47] 250 Directory successfully changed.
[03:08:47] PWD
[03:08:47] 257 "/dr"
[03:08:47] TYPE A
[03:08:47] 200 Switching to ASCII mode.
[03:08:47] PORT 212,129,102,62,14,135
[03:08:47] 200 PORT command successful. Consider using PASV.
[03:08:47] LIST -aL
[03:08:48] 150 Here comes the directory listing.
[03:08:48] 383 bytes transferred. (N/A/s) (0 ms)
[03:08:48] 226 Directory send OK.
[/codebox]

Could you help with the problem? Thanks...