Connection refused using WiFi

Hi members of the FZ forum,

this is my first post here so please keep that in mind
I have successfully setup an SFTP connection to my seedbox at home [using a cable and using the wireless connection]

I have used the very same settings here at my dorm and i can connect using my desktop pc using a wired vpn connection
But when I use my laptop and try to connect using SFTP over the WiFI of the dorm it doesn't work

This is a paste forom the log:
2013-04-26 23:52:31 3652 11 Status: Connecting to *****.seedunlimited.com:18422...
2013-04-26 23:52:31 3652 11 Response: fzSftp started
2013-04-26 23:52:31 3652 11 Command: open "*****@*****.seedunlimited.com" 18422
2013-04-26 23:52:32 3652 11 Error: Network error: Connection refused
2013-04-26 23:52:32 3652 11 Error: Could not connect to server

Additional info;
OS: Win 7 Ultimate x64 [freshly installed a month ago]

I don't think it's a driver issue or firewall [i'm using the default one from window7 and even dissabled that one and tried to connect]
I have acces to internet using the WiFI of the dorm.

If you need more information [about the kind of WiFi connection or so] I'll do my best to provide accurate info.

EDIT: Is it possible to check which ports are blocked when using wifi? [The WiFi is managed by my university, so my hands are tied if i want to do something]
EDIT2: I can connect to my seedbox using an SFTP connection with my laptop at home