Form Publishing Problem

[Nic]

Hi
We have a Sharepoint site hosted on a server external to our network. I can
add documents, images, to this site no problem from within our network BUT
when I try to publish a form from within the network I get an error message
telling me i've entered an incorrect url or there's a problem with my proxy
settings.

If I go on to a dialup connection I can publish the form. If I then go back
onto the network I can download the form, make changes, however when I go to
save the form I get another message telling me that I haven't got access to
the web folder.

It seems there's a problem getting information out through the network. Is
there a way around this? These forms will be used by 25 other people
accessing them from different networks around the country - is this going to
be an even bigger problem.

From within the network I am able to download the form, save it to my
hard-drive, and then go through the 'manual' upload process and that works
but I would prefer to be able to save straight to the form library. Any ideas?

Thanks