FlashFXP Behind Uni Proxy Problems...

[Idyll]

Hi.
I'm using FlashFXP to upload to several different webspaces (storing pics, 2 different websites, etc) - they're stored on different ftp's because of space limitations / mysql limitations.

My Info:
* FlashFXP v3.0 unregistered - same problem on v.1.3
* OS WinXP
* Running behind NAT/router - University Proxy
* Running firewall - No
* Running Antivirus - Yes Norton2004
* Network - LAN

Basically I configured FlashFXP to run through the uni proxy correctly afaik proxy/firewall > user with no login > then entered the uni ftp info and port.

This allows me to connect to my blueyonder ftp and also my website host (veushosting.com) without any problems

Connecting to ftp.pwp.blueyonder.co.uk via Proxy
Connected to Proxy ftpproxy.***.ac.uk Port 8021
220 server ready - login please

However, when trying to connect to either my Tiscali webspace (ftp.myweb.tiscali.co.uk) or another webhost's space, it says:

Connecting to ftp.myweb.tiscali.co.uk via Proxy
Connected to Proxy ftpproxy.***.ac.uk Port 8021
220 server ready - login please
USER ****@tiscali.co.uk@***ipaddress***
331 password required
PASS (hidden)
500 service unavailable
Connection attempt failed.

^^ I blanked out the usernames and IP addresses.

I've tried messing about with active/passive transfer methods, but tbh I don't really have a clue what I'm doing.

All four of these ftp accounts worked when I was at home and not behind this proxy. Its just strange that only two work now.
Any ideas?

[MxxCon]

in this case PASV/PORT mode will make no difference becuase you are not even connected yet.
500 service unavailable is a reply from your server.
you'll need to contact admin of that server to figure out exactly what's going on