MLSD Problem revisited

Sorry, but I've dome hours of research and can't find the answer:

Filezilla was flawless until I upgraded to 3.5.3. I have two (2) remote servers and FZ gets stuck at MLSD on both. I've tried with no firewall (ZoneAlarm) or AntiVirus (AVG). I've also reinstalled FileZilla and ZoneAlarm.

I used the same FZ 3.5.3 download on two other computers running XP and 7 and everything is fine.

My configuration hasn't changed unless stated:

Win 7 Home - there were a couple of updates between working and not working.
Mobile 3G Modem - Vodafone.
ZoneAlarm updated, but turned off during testing.
AVG unchanged, but also turned off.

Both servers came back Okay using http://www.web2ftp.com.

Could the modem my be ready to spit the dummy.

The Verbose logging shows:

257 "/" is your current location
Trace: CFtpControlSocket::ResetOperation(0)
Trace: CControlSocket::ResetOperation(0)
Trace: CFtpControlSocket::ParseSubcommandResult(0)
Trace: CFtpControlSocket::ListSubcommandResult()
Trace: CFtpControlSocket::SendNextCommand()
Trace: CFtpControlSocket::TransferSend()
Command: TYPE I
Trace: CFtpControlSocket::OnReceive()
Response: 200 TYPE is now 8-bit binary
Trace: CFtpControlSocket::TransferParseResponse()
Trace: CFtpControlSocket::SendNextCommand()
Trace: CFtpControlSocket::TransferSend()
Command: PASV
Trace: CFtpControlSocket::OnReceive()
Response: 227 Entering Passive Mode (74,50,25,220,191,76)
Trace: CFtpControlSocket::TransferParseResponse()
Trace: CFtpControlSocket::SendNextCommand()
Trace: CFtpControlSocket::TransferSend()
Command: MLSD
Trace: CTransferSocket::OnConnect
Trace: CTransferSocket::OnConnect
Error: Connection timed out
Trace: CFtpControlSocket::ResetOperation(2114)
Trace: CControlSocket::ResetOperation(2114)
Trace: CFtpControlSocket::ResetOperation(2114)
Trace: CControlSocket::ResetOperation(2114)
Error: Failed to retrieve directory listing

Any thoughts will be appreciated.