Dell 8500 and smartftp

I've been using SmartFTP for a couple of years without any problems, I've started working for a company and they have bought me a Dell 8500 so I've loaded the latest SmartFTP as my previous version comes up with an error message. I get the following message when I try to connect to our website, Dell reckon it's SmartFTP, my host reckons it's Dell, I don't know either way? My LAN works, it seems to be outside the server? Anyone else had a similar problem please? I want to purchase SmartFTP but am cautious with this problem as my host says he's had problems loading SmartFTP on his own PC.

Error Message

A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
Cannot login waiting to retry (30s)