You don't actually have a connection at all and the browser is looking for a connection that doesn't exist. The IP addresses entered for your service provider aren't correct, so it is looking for a proxy that doesn't exist for that particular address. This problem is usually due to the number of people connected to the ftp site is too large. Try connecting a little bit later, since even if you got on and there were heaps of other users, you'd have problems downloading files. Check that the site you are trying to get to is correct and that it exists.
Many sites disappear from time to time or only allow a select few to connect at any onetime.
Check that you are logging in as anonymous, ftp or guest. It may be that the site you are trying to get to won't let you on because you need a specific login and password. If this is the case, try another site which has the same sort of file you are looking for. This is quite tricky and if it becomes a huge hassle, you would have to disable it. Try a different modem string especially if it seems that it connects and drops out straight away.