Timed Out...Help!

Well, its very odd - I am sure it is a problem with my network here but I can't understand what it may be, perhaps one of you might have a suggestion. Everytime I go to log into my server via FTP it times out on me, but only for this server an only on these computers. It never used to do it untill recently. Here is the log from Smart FTP (this was attempted on a WinNT server that has direct access to the DSL line)

Resolving host name 69.6.238.29...
Connecting to (69.6.238.29) -> IP: 69.6.238.29 PORT: 21
Connected to (69.6.238.29) -> Time = 109ms
Socket connected waiting for login sequence.
220 ProFTPD 1.2.9 Server (Main FTP Server) [web18.opentransfer.com]
USER XXX
331 Password required for XXX.
PASS (hidden)
230 User XXX logged in.
SYST
215 UNIX Type: L8
FEAT
211-Features:
MDTM
REST STREAM
SIZE
211 End
PWD
257 "/" is current directory.
TYPE A
200 Type set to A
PASV
227 Entering Passive Mode (69,6,238,29,218,127).
Opening data connection IP: 69,6,238,29,218,127 PORT: 55935.
A socket operation was attempted to an unreachable host.
PORT 168,103,67,113,161,201
200 PORT command successful
Opening data connection IP: 168.103.67.113 PORT: 41417.
LIST -aL
Connection closed. Server timeout.
NOOP
Connection closed. Server timeout.
Command aborted. Server timeout.
NOOP
Connection closed. Server timeout.
Command aborted. Server timeout.
425 Unable to build data connection: Connection timed out

Any thoughts on what this might be? And how I might go about fixing it?