Transfer failed when resuming download

I've used SmartFTP for quite some time, usually with no problems. But lately I've encountered problems resuming downloading. I've read questions posted here but either they're not quite my problem, or I didn't understand much what was said.
The problem has happened mostly with one specific FTP address. Files are large and whenever I try resuming I get the message "Transfer failed". I'm copying the log below:

[20:24:44] SmartFTP v2.5.1008.25
[20:24:44] Resolving host name "206.209.212.25"
[20:24:44] Connecting to 206.209.212.25 Port: 21
[20:24:44] Connected to 206.209.212.25.
[20:24:44] 220 bbkossubftp01 X2 WS_FTP Server 6.0(13051250)
[20:24:44] USER Proj003192
[20:24:45] 331 Enter password
[20:24:45] PASS (hidden)
[20:24:45] 230 User logged in
[20:24:45] SYST
[20:24:48] 215 UNIX
[20:24:48] Detected Server Type: UNIX
[20:24:48] FEAT
[20:24:48] 221-Extensions supported
[20:24:48] SIZE
[20:24:48] XMD5
[20:24:48] XSHA1
[20:24:48] XSHA256
[20:24:48] XSHA512
[20:24:48] LANG EN, ES, FR, GE
[20:24:48] MDTM
[20:24:48] MLST size*;type*;perm*;create*;modify*;
[20:24:48] REST STREAM
[20:24:48] TVFS
[20:24:48] UTF8
[20:24:48] AUTH SSL;TLS-P;
[20:24:48] PBSZ
[20:24:48] PROT C;P;
[20:24:48] 221 end
[20:24:48] Detected Server Software: WS_FTP Server 3.x
[20:24:48] SITE UTF8
[20:24:49] 200 Command SITE succeed
[20:24:49] PWD
[20:24:50] 257 "/users/Proj003192" is current directory
[20:24:55] TYPE I
[20:24:56] 200 Transfer mode set to BINARY
[20:24:56] SIZE vertigo_v00917819_pal.mpg
[20:24:57] 200 531507811
[20:24:57] MDTM vertigo_v00917819_pal.mpg
[20:24:58] 213 20071207170658
[20:24:58] No rule matched. Default Action="Ask".
[20:25:00] PORT 192,168,2,4,4,91
[20:25:04] 200 Command PORT succeed
[20:25:04] REST 212003640
[20:25:04] 110 Restart from 212003640
[20:25:04] MDTM vertigo_v00917819_pal.mpg
[20:25:05] 213 20071207170658
[20:25:05] Transfer failed. Use the Transfer Queue for automatic retries.

The two last lines are the ones I keep getting. I've tried changing either to passive and active modes. No success. And I'm using the latest version of SmartFTP.
Tks.

The software running on the server (WS_FTP server) is buggy:

[20:25:04] REST 212003640
[20:25:04] 110 Restart from 212003640

The 110 reply from the server is just plain wrong.
Reference: RFC 959 Page 51 and 56
[url="http://www.ietf.org/rfc/rfc0959.txt"]http://www.ietf.org/rfc/rfc0959.txt[/url]

A workaround for the incompetence of the developers of WS_FTP Server will be in the next build.

Regards,
Mat